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Early husbandry practices that include herd management and the use of livestock areas such as sheepfold caves can be analysed in the context of different disciplines (e.g. zooarchaeology, micromorphology, and archaeobotany). In this study, a new and standard method for the determination of bile acids and steroidal hormones that incorporates microwave extraction-liquid chromatography-mass spectrometry was used. This method has been applied successfully to analyse Neolithic fumier deposit facies from the El Mirador cave, a location that was used as a prehistoric sheepfold and is located in the Atapuerca range (Burgos, Spain). The results obtained demonstrated that the analysis of bile acids can be useful for the identification of remains of ruminant residues in the facies studied. In addition, the progesterone/deoxycholic acid ratio has been used as a possible biomarker to improve our understanding of flock management, including the separation of pregnant and nursing ewes from the rest of the herd to avoid the rejection of the lamb and keep them safe and healthy. The authors thank the technical and human support provided by the Alava Central Service of Analysis of SGIker (UPV/EHU, MINECO, GV/ EJ, ERDF, and ESF) and Paula Rivero for the elaboration of the graphical abstract. Patricia Martín is grateful for her postdoctoral fellowship to Juan de la Cierva Subprogramme (FJCI-2016-29045) with financial sponsorship from the Spanish Ministry of Economy, Industry, and Competitiveness and for her recent "Maria de Maeztu" excellenceaccreditation from the Spanish Minstry of Science and Innovation (CEX2019-000945-M), and to Ane Gorostizu-Orkaiztegi for her pre- doctoral fellowships to the University of the Basque Country. This work was funded by the Department of Industry, Innovation, Commerce, and Tourism of the Basque Government (SAI12/25 Project), the Spanish Ministry of Science, Innovation and University (PGC 2018-093925-B- C32 project) and by the Basque Government, Research Groups of the Basque University System (Project No. IT925-16).

[EN]The production of artificial anti-CB1 antibodies in nanoparticle format is described using the solid-phase imprinting approach. Instead of whole protein imprinting, a linear C-terminus sequence of the receptor comprising 15 amino acids (458-KVTMSVSTDTSAEAL-472) has been used as template, in accordance with the epitope imprinting approach. This sequence is located intracellularly, and it is involved in coupling to G(i/o) proteins, being responsible for CB1 receptor desensitisation and internalisation. Developed molecularly imprinted materials were found to be in the nanometre scale, with a particle size of 126.4 +/- 10.5 nm at pH 3 (25 oC) and spherical shape. It was also observed that the size was sensible to temperature changes being reduced to 106.3 +/- 15.2 nm at 35 degrees C. Lower critical solution temperature of this polymer was found to be approximate to 33.4 degrees C. The affinity and selectivity of the artificial antibody were assessed through dot blot and Western blot experiments. For the latter, recombinant fusion proteins GST-CB1(414-472) and GST-CB1(414-442) were produced to work respectively as target and negative control proteins. The control protein did not carry the target epitope for being devoid of last 30 amino acids at the C-terminus. The results demonstrated that the anti-CB1 material recognised selectively the target protein, thanks to the presence of the 15-amino acid sequence selected as epitope, which revealed that binding occurred at the C-terminus of the receptor itself. The methodology presented may pave the way for the development of novel imprinted nanomaterials for other proteins included in the superfamily of the G-protein-coupled receptors (GPCR). Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Funding for this research was provided by the Spanish Ministry of Science, Innovation and Universities (project CTQ2017-85686-R) and by the Basque Government (Research Groups of the Basque University System, Project No IT 1186-19.

Molecularly imprinted polymers (MIP) have attracted considerable attention as smart materials so far. They are known to be capable of imitating the recognition event that happens biologically in living organisms and, in this light, they have noteworthy been used as substitutes of natural receptors. Traditionally, imprinted polymers have been developed by bulk free radical polymerization (FRP), obtaining rigid polymers, which are lately ground to get fine particles. Bulk synthesis of imprinted polymers was substituted by other polymerization approaches in order to overcome typical drawbacks associated with bulk MIPs. Recently, new polymer syntheses have emerged such as solid phase imprinting which have allowed for obtaining smart materials with higher affinity for the target ligand, achieving binding affinities similar or even higher than natural receptors. Materials obtained this way are known as plastic antibodies. This chapter focuses on recent advances on imprinted polymers as potential substitutes of natural receptors, emphasizing on new synthesis strategies and novel imprinted nanomaterials.

The assessment of chronic kidney disease (CKD) is performed by means of glomerular filtration rate (GFR), which is calculated from equations using serum creatinine concentration. However, serum creatinine concentration changes according to several factors, and this might endanger CKD diagnosis, especially in early stages of the disease. In addition to metabolic and cardiovascular complications, CKD is related to growth complications and malnutrition. All of these complications lead to a 30 times higher mortality rate in paediatrics suffering from advanced CKD compared to healthy counterparts. Overall, the existence of biomarkers for a defined disease allows earlier diagnosis as well as better response. For that reason, comprehensive research has been performed in adults suffering from CKD aimed at finding new biomarkers, however only a few studies are available in paediatrics with CKD so far, and there is a need for new biomarkers in this population. For that purpose, following targeted and untargeted metabolomics approaches seven potential biomarkers have been found which could be useful for paediatric CKD by comparing metabolic profiles. The use of these metabolites in addition to creatinine enables better differentiation of paediatrics with CKD and control ones, unlike just creatinine itself.; Giltzurrun gutxiegitasun kronikoaren (GGK) ebaluazioa egiten da iragazpen glomerularraren tasaren (IGT) bidez, eta kalkulatzen da serumeko kreatininaren kontzentrazioan oinarritutako ekuazio ezberdinen bidez. Hala ere, serumeko kreatinina kontzentrazioa hainbat faktoreren arabera alda daiteke, eta honek GGKaren diagnostikoa arriskuan jar dezake, bereziki gaixotasunaren fase goiztiarrenetan. Haurretan GGKak arazo metaboliko eta kardiobaskularrez gain, garapen-arazoak eta malnutrizioa eragiten ditu. Haur osasuntsuekin alderatuta, zailtasun horiek 30 aldiz handitzen dute heriotza-tasa GGKaren fase aurreratuenetan dauden haurretan. Orokorrean, gaixotasun jakin baterako biomarkatzaileen presentziak diagnostiko goiztiarragoa eta erantzun hobea ahalbidetzen dute. Hori dela eta, GGK pairatzen duten helduetan ikerketa integrala egin da biomarkatzaile berriak topatzeko, baina populazio pediatrikoan ikerlanak oraindik oso mugatuak dira eta biomarkatzaile berrien beharra dago. Helburu horrekin, haur osasuntsuen eta GGK pairatzen duten haur gaixoen arteko profil metabolikoen konparaketa egin da, metabolomika bideratu zein ez-bideratuak aplikatuz. Ikerketaren ondorioz, GGK pediatrikoaren detekzio goiztiarrean erabilgarri izan daitezkeen zazpi metabolito berri aurkitu dira, kreatinina biomarkatzaile klasikoarekin batera. Metabolito horiek, kreatininarekin batera erabiliz, kreatinina soilaren erabilerarekin alderatuz haur gaixoen eta osasuntsuen artean bereizketa egitea ahalbidetzen dute.

Herein, a straightforward approach for the controlled coating of gold microelectrodes with molecularly imprinted polymer (MIP) thin films is presented. To this end, a new iniferter has been synthesised, 3-mercaptopropyl diethylcarbamodithioate, which contains terminal thiol groups capable of forming self-assembled monolayers (SAM) on gold substrates. The iniferter SAM was activated under UV radiation after the immersion of the microelectrode in the polymerisation solution, containing 4-ethylphenol (4EP) as template and 4-vinylpyridine and ethylene dimethacrylate as functional monomer and cross-linker respectively. The voltammetric behaviour of the resulting MIP-coated microsensor was assessed next, finding that electrochemical response was linear to the concentration of the target analyte (4EP) in a range comprised between 10−6 and 10−3 mol L−1, showing a sensitivity of 1.02 ± 0.02 (nA L μmol−1) (R2: 0.9983). Measurement repeatability was also evaluated performing a series of measurements with the same sensor at two concentrations levels of 4EP, 5 × 10−6 mol L−1 and 10−4 mol L−1, obtaining relative standard deviations (RSD) of 3.41% and 1.92% respectively. Similarly, sensor-to-sensor repeatability was also determined obtaining RSD values of 10.02% and 16.97% respectively. Sensor selectivity was finally studied comparing the peak current intensity of 4EP with current intensities registered with structural analogues. It was found that sensor was capable of discriminating the target compound from structural analogues presenting remarkable selectivity, even for almost identical compounds such as 4-vinylphenol.

The work presented here explores the grafting of molecularly imprinted nanoparticles (MIN) on silica beads for the development of new chiral stationary phases (CSP). Both solid-phase imprinting and precipitation polymerisation were tested for MIN synthesis though the latter approach was the only one that provided efficient chiral selectors. MIN particles were prepared by iniferter polymerisation initiated by UV radiation, using itaconic acid as functional monomer and ethylene dimethacrylate as cross-linker. This resulted in particles with an average size of 249.0 ± 4.0 nm which were covalently immobilised onto chromatographic silica beads. The resultant CSP based on the composite silica beads-MIN was capable of resolving the racemate of the antidepressant drug citalopram and also separating its major metabolites by liquid chromatography, with better efficiency and peak symmetry than other MIP based CSP. The methodology presented here allowed for the quantification of the pharmacologically active enantiomer (+)-(S)-citalopram (SCIT) and its main metabolites (+)-(S)-desmethylcitalopram (SDCIT) and (+)-(S)-didesmethylcitalopram (SDDCIT) in urine, registering mean recoveries that ranged from 91.5 to 103.7% with RSD values that were below 10% in all tested concentration levels (0.1, 0.75 and 5 μg mL−1), which confirmed method suitability for the intended application.

Systematic fungicides treatments in vine-growing European ecosystems have been conducted for decades. The goal of this study was to determine the mobility and persistence of 20 fungicides used in two viticultural zones in Atlantic and Mediterranean climates, from the moment of their application until their distribution throughout different compartments of the ecosystem: soil, water, grapes, musts and wines. This study also sought to obtain valuable information to reduce the usage of these products without affecting the health of the vines. For this purpose, different phytosanitary treatments were applied, using dosing criteria based on data provided by meteorological stations, degree-day accumulation, phenological state, and growers' criteria. The observed differences between studied geographical areas were not significant with regard to chemical accumulation in the soil and water; however, they were significantly different regarding to grapes, musts, and wines.

Grapevine and derived products are rich in a wide range of compounds and its quality mainly depends on its metabolites, as a result of viticulture practices. Plant sterols, also called phytosterols (PS), are secondary metabolites regarded as bioactive substance present in grape berries and other plant-based food. The present study deals with a metabolomic approach focusing on phytosterols family in six varieties of Rioja grapes (Cabernet Sauvignon, Tempranillo, Graciano, Garnacha, White Garnacha and Viura), in order to find significant differences among them. Liquid chromatography- mass spectrometry with a quadrupole-time of flight mass analyzer (LC-QTOF) was used to find as many metabolites as possible in the different grape berry fractions, and using statistics to help finding significant clustering of the metabolic profile of pulp, peel and seeds in relation to the variety. The best chromatographic and detection conditions were achieved by gas phase ionization via atmospheric pressure chemical ionization (APCI) in positive mode. Furthermore, analysis with electrospray (ESI) is also needed for phytosterol derivatives confirmation. Putative compounds of interest in the analyzed samples were found by an automated compound extraction algorithm (Molecular Feature Extraction, MFE) and an initial differential expression from the data was created with the aid of commercial software. Once the data were collected, the results were filtered, aligned and normalized, and evaluating applying one-way analysis of variance (ANOVA) with a 95% significance level. For sample class prediction, partial least square-discriminant analysis (PLS-DA) is used as a supervised pattern recognition method and excellent separation among the grape varieties is shown. An overall accuracy of 93.3% (pulp samples), 100.0% (peel) or 96.7% (seeds) in discriminating between grape varieties was achieved when comparing the different fractions. In general, 7 PS derivatives were identified with ID scores higher than 84%.

This paper reports the development of stir bars with a new MIP based coating, for the selective sorptive extraction of the herbicide glyphosate (GLYP). Molecular imprinting of the polymer has directly been carried out employing underivatised GLYP as the template molecule. Due to the poor solubility of the target compound in organic solvents, the MIP methodology has been optimised for rebinding in aqueous media, being the synthesis and the rebinding steps carried out in water:methanol mixtures and pure aqueous media. The coating has been developed by radical polymerisation initiated by UV energy, using N-allylthiourea and 2-dimethyl aminoethyl methacrylate as functional monomers and ethylene glycol dimethacrylate as the cross-linker. Mechanical stability of the coating has been improved using 1,3-divinyltetramethyldisiloxane in the polymerisation mixture. Under the optimised conditions, the MIP has demonstrated excellent selectivity for the target compound in the presence of structural analogues, including its major metabolites. The applicability of the proposed method to real matrices has also been assessed using river water and soil samples. Registered mean recoveries ranged from 90.6 to 97.3% and RSD values were below 5% in all cases, what confirmed the suitability of the described methodology for the selective extraction and quantification of GLYP.

In this work, the development of a novel enantioselective sensor is described using chiral imprinted nanoparticles as recognition elements. Imprinted nanoparticles, synthesised via precipitation polymerisation, were incorporated in a polyvinyl chloride membrane which served as the sensing element to construct a potentiometric sensor selective to the S enantiomer of the antidepressant drug citalopram (SCIT). The effect of the amount of nanoparticles, the type and quantity of plasticiser and the concentration of the internal reference solution were assessed in order to have a sensor with best sensor performance. The fabricated sensor showed Nernstian behaviour with a slope of 50.77 ± 1.32 mV decade −1 in SCIT + solutions that ranged from 2.5 × 10 −7 to 10 −3 mol L −1 . Sensor applicability to urine samples was also tested using spiked urine samples as quality control samples as well as urine collected from a volunteer who had been treated with this drug. The fabricated sensor was capable of accurately determining SCIT + with good precision (RSD 2.07–6.56%) at different concentration levels.

Chronic kidney disease (CKD) is a major epidemiologic problem which causes several disturbances in adults and in pediatrics. Despite being a worldwide public health problem, information available for CKD in the pediatric population is scarce. For that reason, an ion-pair reversed-phase liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) method has been developed and validated in order to analyze 16 amino acids, amino acid derivatives, and analogous compounds related to the arginine-creatine metabolic pathway that are suspicious of being increased or decreased in plasma from patients with CKD. The analytical method involved the addition of dithiothreitol, a reducing agent which reduces disulfide and thus giving total aminothiol concentration, as well as a simple precipitation of plasma proteins. Moreover, despite amino acids being usually derivatized to improve their retention time and to enhance their signal, for this method, an ion-pairing reagent was used, thus avoiding the need for derivatization. Subsequently, analysis of plasma from pediatric patients suffering from CKD and control pediatrics was carried out. As a result, glycine, citrulline, creatinine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) were significantly increased in patients with CKD, regardless of their creatinine level, whereas in addition to these compounds dimethylglycine was also increased when CKD patients had plasma creatinine concentrations above 12 μg mL(-1), thus all are suggested as potential biomarkers for renal impairment.

The aim of the present study is the identification of plant sterols and the development of an analytical method that allows for the quantification of such family of compounds in oenological matrices. The application of liquid chromatography-atmospheric pressure chemical ionization ion-trap mass spectrometry (LC-APCI-ITMS) to sterol characterization is a useful tool and was selected to perform this research. Sterol separation was achieved using a C8 column with a mobile phase consisting of water and acetonitrile under gradient conditions and column temperature of 35 °C, which leads to analyte elution in less than 25 min. Retention times, precursor ions and MRM transitions of analytes allowed for the identification and sensitive quantitative determination of phytosterols in oenological matrices at trace levels. The method showed a dynamic linear range over the concentration ranges from 0.02 to 320 mg kg−1 for the different parts of grapes and from 8 to 100 ng mL−1 in case of wine. The most abundant phytosterol in all samples was β-sitosterol. The seeds are the richest source of phytosterols having a great amount of β-sitosterol, 314 mg kg−1 fresh berry mass, followed by stigmasterol, fucosterol and campesterol at much lower concentrations (ranging from 3 to 10 mg kg−1).

A surface-imprinted chiral stationary phase for the enantiomeric resolution of the antidepressant drug, citalopram, is presented in this work. N, N′-diethylaminodithiocarbamoylpropyl(trimethoxy)silane has been used as silane iniferter for the surface functionalization of the solid silica support. A molecularly imprinted polymer thin film, in the nm scale, was then grafted on the silanized silica using itaconic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linker in the presence of the template S-citalopram. The total monomer amount was calculated to obtain the desired thickness. Non-imprinted stationary phases were prepared similarly in the absence of S-citalopram. Characterization of the materials was carried out by scanning electron microscopy, thermogravimetric analysis, elemental analysis and Fourier transform infrared spectroscopy. Stationary phases have been applied to the chromatographic separation of the target. Conditions for best chromatographic resolution of the enantiomers were optimized, and it was found that a mobile phase consisting of a mixture of formate buffer (40 mM, pH 3) and acetonitrile (30:70 v/v) at 40 °C provided best results. Binding behaviour of the developed material was finally assessed by batch rebinding experiments. The obtained binding isotherm was fitted to different binding models being the Freundlich–Langmuir model, the one that best fitted the experimental data. The developed material has shown high selectivity for the target enantiomer, and the stationary phase could be undoubtedly exploited for chiral separation of the drug. Copyright © 2015 John Wiley & Sons, Ltd.

The identification of characteristic organic gunshot residues (OGSR) provides conclusive evidence in the elucidation of elemental profiles when lead-free ammunition is fired. OGSR also prevents false negatives. Toward this aim, a quick and efficient method based on liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF) was developed to detect and identify 18 gunpowder additives in gunshot residues (GSR). The unequivocal identification of target analytes was assured by using MS/MS mode. Swabs were compared with home-modified tape lift supports covered with a PTFE layer to determine the better sampling technique. The modified tape lift provided better extraction recoveries and enabled the analysis of inorganic and organic GSR simultaneously. The developed method was applied to the analysis of GSR from four different lead-free ammunitions. Diphenylamine and its nitrated degradation products and centralites were identified in all samples, providing strong evidence of GSR.

The characterization of ancient lipids from prehistoric sediments (fumiers) located in a rock-selter has been possible after the optimization of an analytical method based on the microwave-assisted extraction and solid-phase extraction clean-up step and a final derivatization step followed by gas chromatography with mass spectrometry. Eight sterols and two bile acids were detected just in the partially burned and unburned layers of the fumiers (animal organic residues deriving from manure/dung). The relationship between some of these compounds can be used to distinguish the biogenic origin of the samples, concluding that these strata (from Early Neolithic to Late Chalcolithic/Early Bronze Age) can be classified as ruminant residues. Three main periods of activity are observed over a period of 2000 years: one from 3990 ± 40 before present (4530-4410 calibrated before present) to 4100 ± 40 before present (4820-4750/4730-4510/4470-4450 calibrated before present), the second from 4470 ± 40 before present (5300-4970 calibrated before present) to 5490 ± 30 before present (6310-6275/6230-6220 calibrated before present) and the third from 5880 ± 30 before present (6775-6765/6750-6645 calibrated before present) to 6010 ± 30 before present (6940-6780/6765-6755 calibrated before present). Chemical data obtained are in concordance with the previous results obtained in the area.

Environmental pollution by mercury in ambient water samples is a recognized problem worldwide. Sample preservation and transport to the laboratory lead to uncertain analytical results. This study outlines the development of a procedure for on-site electrodeposition of mercury from water samples on a screen-printed gold electrode (SPGE) using portable voltammetric techniques. Once in the laboratory, Hg is analyzed by laser ablation inductively coupled plasma-mass spectrometry (LA-ICPMS) in order to ensure that the required sensitivity and precision levels for environmental sample analysis are reached. A new ablation chamber was intentionally designed for the analysis of SPGE's gold electrode. This cell has a small internal volume of 15 cm3 and the SPGE device perfectly fits inside. This design assures signal stability, avoids elemental fractionation and reduces wash-out time to a few seconds, reducing the analysis time considerably. The proposed method is capable of measuring dissolved mercury at the ng L-1 level (quantification limit 200 ng L-1) with good precision (RSD < 7.6%). The proposed method was tested with the NCS ZC 76303 (NIM-GBW08603) Mercury in water Certified Reference Material.

A new potentiometric sensor based on molecularly imprinted nanoparticles produced via the solid-phase imprinting method was developed. For histamine quantification, the nanoparticles were incorporated within a membrane, which was then used to fabricate an ion-selective electrode. The use of nanoparticles with high affinity and specificity allowed for label-free detection/quantification of histamine in real samples with short response times. The sensor could selectively quantify histamine in presence of other biogenic amines in real wine and fish matrices. The limit of detection achieved was 1.12×10(-6)molL(-1), with a linear range between 10(-6) and 10(-2)molL(-1) and a response time below 20s, making the sensor as developed a promising tool for direct quantification of histamine in the food industry.

Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) is a rare ischemic disease that affects the optic nerve. Pathophysiology and mechanism of ischemia of NAION remain uncertain, so the aim of this work is to establish the first metabolic fingerprinting of patients with NAION to discover possible new biomarkers. Twenty-four patients, aged 39–85 years, diagnosed with NAION, after a sudden loss of vision, were recruited for the study. Plasma samples of patients and controls were fingerprinted with liquid chromatography coupled to quadrupole time-of-flight by electrospray ionization, and obtained data were filtered, aligned and statistically analysed to identify new biomarkers. The identity of compounds that were found to be significant in class separation was later confirmed by obtaining the characteristic MS/MS spectra and online databases. In general, biochemical and metabolic profiles between patients and controls did not show profound differences, but NAION patients presented disturbances in the phospholipid composition which lead to reduced plasma values of LysoPCs. Altered levels of other metabolites, such as l-Palmitoylcarnitine, have been detected and could be considered as potential biomarkers.

A method based on scanning laser ablation and inductively coupled plasma-mass spectrometry (SLA-ICPMS) and Raman micro-spectroscopy for the detection and identification of compounds consistent with gunshot residue particles (GSR) has been developed. The method has been applied to the characterization of particles resulting from the discharge of firearms using lead-free ammunition. Modified tape lifts were used to collect the inorganic and organic residues from skin surfaces in a single sample. Using SLA-ICPMS, aggregates related to the composition of the ammunition, such as Cu-Zn-Sn, Zr-Sr, Cu-Zn, Al-Ti, or Al-Sr-Zr were detected, but this composition is only consistent with GSR from lead-free ammunitions. Additional evidence was provided by micro-Raman spectroscopy, which identified the characteristic organic groups of the particles as centralite, diphenylamine or their nitrated derivatives, which are indicative of GSR.

This paper reports the application of a chiral imprinted polymer (CIP)-coated stir bar for the selective extraction of (+)-(S)-citalopram (SCIT) and its main metabolites, (+)-(S)-desmethylcitalopram (SDCIT) and (+)-(S)-didesmethylcitalopram (SDDCIT), from urine samples. The developed device has been demonstrated to be capable of selectively extracting the three target analytes from urine samples without saturating the imprinted sites. A CIP-coated stir bar sorptive extraction procedure (CIP-SBSE) is proposed for the isolation of SCIT, SDCIT and SDDCIT followed by their subsequent analysis using liquid chromatography ion trap mass spectrometry (LC-ITMS). Deuterated SCIT-d6 was used as an internal standard. The method was validated using a standard procedure, which revealed that a quantification of 5 ng mL(-1) was obtained in urine samples and that the accuracy and precision were within the established values while no matrix effect was observed.

In recent years, Cr speciation in dietary supplements has become decisive in the evaluation of their health risks. Despite being an beneficial micronutrient, Cr(III) can be toxic at living organisms at high concentrations, while Cr(VI) is known to be highly toxic and carcinogenic. The main objective of this work was to optimize an analytical methodology for the extraction and accurate quantification of Cr(III) and Cr(VI) in dietary supplements. The extraction of Cr species was carried out with 50mM EDTA solution on a hotplate under optimized conditions. Special attention was paid to bidirectional species transformations. No noticeable oxidation of Cr(III) into Cr(VI) was observed and the reduction to Cr(III) only occurred at very high Cr(VI) concentrations. Cr(III) as Cr(EDTA)(-) complex was chromatographically separated from Cr(VI), retained as CrO4(2-), on an anion exchange column coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS). The limit of quantification (0.08µgg(-1)) was below the limit established for Cr enriched yeasts by the European Union. Eleven dietary supplements were analyzed and Cr(III) and Cr(VI) quantification was carried out by external calibration monitoring (52)Cr isotope and by speciated isotope dilution mass spectrometry (SIDMS) adding (50)Cr(III) and (53)Cr(VI) spikes. Total Cr was also quantified by ICP-MS and mass balance between total Cr and the sum of Cr(III) and Cr(VI) was achieved. In eight of the eleven tested supplements Cr(III) calculated amounts were higher than those indicated by the manufacturer, but only one of them exceeded the 250µgday(-1) recommended by World Health Organization (WHO). In contrast, it is worth noting that Cr(VI) amounts beyond the recommendations of the European Union for Cr enriched yeasts were found in five supplements. These results revealed that more accurate and rigorous quality assurance protocols should be applied to the testing of the final products, including the analysis of both Cr(III) and Cr(VI).

A new method based on scanning laser ablation and inductively coupled plasma-mass spectrometry (LA-ICPMS) for the detection and identification of gunshot residue (GSR) particles from firearms discharges has been developed. Tape lifts were used to collect inorganic residues from skin surfaces. The laser ablation pattern and ICPMS conditions were optimized for the detection of metals present in GSR, such as (121)Sb, (137)Ba, and (208)Pb. Other isotopes ((27)Al, (29)Si, (31)P, (33)S, (35)Cl, (39)K, (44)Ca, (57)Fe, (60)Ni, (63)Cu, (66)Zn, and (118)Sn) were monitored during the ICPMS analyses to obtain additional information to possibly classify the GSR particles as either characteristic of GSR or consistent with GSR. In experiments with real samples, different firearms, calibers, and ammunitions were used. The performed method evaluation confirms that the developed methodology can be used as an alternative to the standard scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) technique, with the significant advantage of drastically reducing the analysis time to less than 66 min.

Environmental pollution by metals is a recognized problem worldwide. As a result of the exposure to this pollution, marine species may bioaccumulate metals in both muscle and fishbone, as has been demonstrated in some species of tuna. The objective of this study has been the development and optimization of an inductively coupled plasma-mass spectrometry (ICP-MS) based method, which allows the quantification of 21 elements including priority pollutants and biologically essential elements (B, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Pd, Cd, Ba, La, Hg and Pb) in muscle and in the first spine of the first dorsal fin of albacore (Thunnus alalunga) and bluefin tuna (Thunnus thynnus). A microwave-assisted digestion has been developed for sample treatment, which has been evaluated using isotope dilution analysis (IDA) of Cr, Se, Cd, Ba and Pb. Evaluation of the analytical method in terms of sensitivity (LOQ between 0.002 and 1 mg kg−1), accuracy and precision within and between days (CV

An electrochemical method for chiral polyaniline synthesis has been optimised to develop voltammetric sensors capable of target enantiomer recognition. The methodologies for both R- and S-specific sensor development have been carefully optimised in order to obtain the highest chiral discrimination capacity. R and S specific sensors were synthesised potentiostatically at 0.5 V and 0.6 V, respectively in 0.28 M R- or S-camphorsulphonic acid, which acted as a chiral inducing agent. Higher potential values led to polymer degradation. The proposed methodology allows the generation of sensors which are able to bind the different enantiomers of the pesticide dinoseb with good sensitivity and repeatability (RSD

A stir-bar sorptive extraction (SBSE) method followed by automated thermal desorption (ATD) coupled to gas chromatography-mass spectrometry was optimized for determining trace levels of 18 synthetic fragrances (musks). Using the method developed a retention time locked library is created and converted to a screening database. This homebuilt database can be combined with deconvolution software for the identification of musks. A factorial design was provide to evaluate the main parameters and interactions between the factors affecting the process of SBSE. Operating with de MS-detector in the full-scan mode, high sensitivity with detection limits in the low ng L(-1) range, and good linearity and repeatability were achieved for all musks. The applicability of the method developed was tested in natural waters (surface and groundwater) and wastewater of a plant treatment (WWPT). The results obtained confirmed the usefulness of the proposed method for the determination and unequivocal identification of musks. This approach enables the developed method to be used for routine screening of environmental samples and posterior rapid quantitation of the positive samples.

The antidepressant citalopram (CIT) is a potent and highly selective serotonin reuptake inhibitor (SSRI) which has been introduced in therapy as a racemic drug. CIT has been used to treat central nervous system affective disorders such as depression, anxiety, obsessive-compulsive disorders, various phobias, borderline personality disorders, bipolar disorders as well as indications wherein inhibition of serotonin reuptake is desired. CIT is demethylated to demethylcitalopram (DCIT) and didemethylcitalopram (DDCIT), which retain considerable activity as SSRIs. Therefore, in recent years, the monitoring of the levels of these analytes in biological fluids for toxicological and therapeutic purposes has been a target worthy of interest. In addition, the differences in activity between CIT enantiomers established the need to assess its behaviour in the field of pharmacological research. It is also necessary to develop analytical methodologies that make it possible to determine the levels of enantiomer concentrations. This review includes most of the published analytical methods for achiral assay of racemic CIT and its metabolites based on high-performance liquid chromatography coupled with UV, fluorescence and mass spectrometry detectors, capillary electrophoresis and gas chromatography with mass spectrometry detectors among others. With regard to the monitoring of enantiomers of CIT and of its metabolites, stereoselective methods based on chiral chromatographic columns, chiral additives in mobile phases and on the derivatization with a chiral reagent are also collected. In addition, different procedures of extraction are mentioned as well as liquid-liquid extraction, solid-phase extraction, solid-phase microextraction, automated online extraction or liquid-phase microextraction in different biological and environmental samples.

The aim of this article is to present a new procedure based on dual solid-phase microextraction (dSPME) for the simultaneous extraction of 16 pharmaceutical compounds with acidic and basic characteristics in urban wastewaters. Water samples are divided into two aliquots of 2 mL each extracted by two CW-TPR fibers at different pH values (pH 3 and 11) and with a NaCl concentration of 300 g L(-1) at 75 degrees C for 30 min. The analytes in both fibers are desorbed one after the other in the desorption chamber in static mode with mobile phase for 10 min. The extracts are injected into an LC system coupled to an ion trap mass spectrometer, leading to the accurate quantification of 16 pharmaceutical compounds in wastewaters, in MS(2) mode. All the target compounds found in wastewaters provide good signals corresponding to the protonated precursor ion [M+H](+). The parameters influencing adsorption and desorption of the analytes on fiber were optimized. The assessment of the analytical method was performed by studying the linearity (LOQ to 10 ng mL(-1)) and the intra- and interday accuracy (89.2-109.7%) and precision (RSD

Molecularly Imprinted poly[tetra(o-aminophenyl)porphyrin] is presented as an electrosynthesized coating for the development of selective microsensors. A carbon fiber microelectrode has been modified with this covering by cyclic voltammetry in the potential range from −0.15 to 1.0 V (scan rate 50 mV s−1) obtaining a microsensor able to recognize the template molecule. To carry out this study dopamine was chosen as model to work with, since this molecule presents electroactivity as it can be oxidized on carbon electrodes. The MIP sensor presented a linear response to the dopamine concentration in the range from 10−6 to 10−4 M with good repeatability (RSD 6.22%). The selectivity shown by the microsensor was found to be excellent as it was able to differentiate between different catecholamines. A method has been developed for the determination of dopamine in brain tissue samples using the MIP microsensor.

A rapid and sensitive method for the speciation and quantification of glucosinolates in rapeseed is described. The method combines liquid chromatography (LC) with ion trap mass spectrometry (ITMS) detection. Electrospray ionization (ESI) has been chosen as the ionization technique for the on-line coupling of LC with ITMS. Glucosinolates are extracted from different rapeseeds with MeOH and the extracts are cleaned-up by solid phase extraction with Florisil cartridges. Aqueous extracts are injected into LC system coupled to an ITMS, leading to accurately quantify eight of the most important glucosinolates in rapeseed, by MS2 mode and confirming their structure by MS3 acquisition. All the glucosinolates found in rapeseeds provide good signals corresponding to the deprotonated precursor ion [M-H]-. The method is reliable and reproducible, and detection limits range from 0.5 nmol g(-1) to 3.7 nmol g(-1) when 200 mg of dried seeds of certified reference material are analyzed. Within-day and between-day RSD percentages range between 2.4-14.1% and 3.9-16.9%, respectively. The LC-ESI-ITMS-MS method described here allows for a rapid assessment of these metabolites in rapeseed without a desulfatation step. The overall process has been successfully applied to identify and quantify glucosinolates in rapeseed samples.

Solid-phase microextraction (SPME) coupled to high performance liquid chromatography (HPLC) and the subsequent detection by inductively coupled plasma-mass spectrometry (ICP-MS) was used as a new approach for the determination of tributyltin (TBT), triphenyltin (TPhT), trimethyltin (TMeT) and tripropyltin (TPrT) in water samples. These organometallic compounds were extracted on a coated fiber and desorbed in static mode in a SPME/HPLC interface. Triorganotin compounds were separated using a mobile phase of water–acetonitrile–acetic acid (50 : 40 : 10) at a flow-rate of 0.3 mL min−1. In order to reduce the solvent loading on the plasma, the spray chamber was cooled to −5 °C and oxygen (0.1 L min−1) was mixed into the make-up gas by a mass-flow controller. The extraction and preconcentration capabilities of SPME and the monitorization of 120Sn isotope signal by ICP-MS during the run provided detection limits ranging between 6 and 185 ng L−1Sn as well as good repeatability (inter-day RSD < 19.23%). This method was applied to the determination of triorganotins in freshwaters and seawater of leisure ports, which demonstrates the usefulness of this technique for organotins.

A carbon fiber microelectrode (CFME) was coated with a polymeric film, in order to synthesize an MIP based voltammetric microsensor for the selective determination of DNOC. The polymeric synthesis was carried out by electrocopolymerization of aniline and o-phenylenediamine (o-PD) in a water:methanol (1:1) media. The response of the MIP-sensor synthesized to the target analyte, was linear in a range from 8 × 10−7 to 10−4 M with a sensitivity of 1.6 × 103 nA M−1 and good stability and repeatability (

Fluoxetine (FLX) and norfluoxetine (NFLX) racemic mixtures were determined by reversed-phase liquid chromatography with fluorescence detection (lambda(exc)=227 nm, lambda(em)=305 nm). The calibration curves prepared from drug-free plasma and brain were linear in the range of 5-1000 ng ml(-1) and 100-40,000 ng g(-1) for doped samples, with detection limits of 3.2 and 2.1 ng ml(-1) in plasma and 31.5 and 26.1 ng g(-1) in brain tissue for FLX and NFLX, respectively. Enantiomer determination was carried out through normal phase HPLC-FD (lambda(exc)=224 nm, lambda(em)=336 nm) after precolumn chiral derivatization with R-1-(1-naphthyl)ethyl isocyanate. Standard curves also prepared in a drug-free matrix were linear for each enantiomer over the range of 2-1000 ng ml(-1) and 20-7000 ng g(-1) with detection limits for the four compounds ranging between 0.2 and 0.5 ng ml(-1) in plasma and between 3.0 and 8.2 ng g(-1) in brain tissue. In both methods the analytes were isolated from the biological matrix by a new solid-phase extraction procedure with recovery in plasma and brain over 90 and 87%, respectively. The repeatability of this extraction procedure was satisfactory within-day and between-day with CV

A molecularly imprinted polymer microsensor was synthesized onto the surface of a carbon fiber microelectrode (CFME) by cyclic voltammetry between −0.1 V and +1.35 V at a scan rate of 50 mV s−1. The monomers aniline and o-phenylenediamine (o-PD) were electrocopolymerized in the presence of the template (metamitron) in an aqueous medium of 0.1 M H2SO4. In order to obtain a sensor with the highest number of imprinted sites as possible, different experiments related to the polymerization process were carried out. The response of the synthesized microsensor was linear to the metamitron in the range between 10−6 and 10−4 with sensitivity of 0.143 nA μM−1 with good repeatability (

A molecularly imprinted polymer (MIP) based methodology is described here for the determination of compounds that belong to the 4-ethylphenol (4EP) metabolic pathway in red wines. To this end, two MIP materials have been developed: a 4EP MIP as a class-selective material to extract phenols that belong to the 4EP metabolic pathway and a coumaric acid (CA) imprinted polymer as a MIP-based stationary phase capable of selectively separating these phenols on HPLC analysis, obtaining clean chromatograms. 4-vinyl pyridine and ethylene glycol dimethacrylate were respectively used as functional monomer and cross-linker for both MIPs. Once polymer compositions were optimised, the 4EP MIP was packed into SPE cartridges for wine sample clean-up and CA MIP was packed into HPLC columns to chromatographically separate the compounds present in the eluates obtained after SPE extraction. The accuracy of the proposed method was tested spiking wine samples with known concentrations of target compounds and subsequently, analytes were quantified by the standard addition method. Registered mean recoveries ranged from 95.2 to 109.2% and RSD values were below 10% in most cases. The described methodology was found to be suitable for the selective extraction and quantification of the compounds that belong to the 4EP metabolic pathway in red wines with minimal matrix effects and could be undoubtedly exploited to monitor 4EP and its precursors in wines.

Three solid adsorbents (Carbotrap, Carbotrap C, and Carbosieve III) were evaluated for sampling trace non-methane hydrocarbons in urban atmospheres. The sampled atmosphere was pumped through a multisorbent tube containing the three sorbents separated by a small amount of silanized glass wool. The trapped compounds were recovered by thermal desorption and analysed by combining cryogenic enrichment with gas chromatography and mass spectrometry. Adsorption/thermal desorption and breakthrough experiments were performed to test their ability to quantitatively trap the light hydrocarbons. The technique was suitable for determination of low ppbv concentrations of these compounds. Ambient atmospheric sampling was conducted in Vitoria-Gasteiz (Basque Country, Spain), and the measurements cover a period of one year (2001–2002). Fifteen C2–C6 hydrocarbons are identified and quantified, and seasonal trends are discussed.

Dimilin 45 ODC (diflubenzuron) was applied in a Mediterranean-climate conifer forest, near Vitoria, Basque Country, Spain. Pine needles were collected at post-treatment 5-day intervals for analysis of the diflubenzuron residues. A liquid chromatography method with on-line diode-array and electrochemical detection was developed for the determination of the pesticide diflubenzuron and its main metabolites: 2,6-diflurobenzamide, 4-chlorophenylurea, 4-chloroacetanilide, 4-chloroaniline and N-methyl-4-chloroaniline in forestry matrices. Aerial application at 56.3 g AI ha−1 resulted in deposition levels of the insecticide of 1080 ng g−1. Within 40-65 days following treatment, 51-73% of the insecticide had been removed from the foliage. During this period, the concentration of diflubenzuron was higher than 295 ng g−1. The only metabolite detected was 2,6-difluorobenzamide and this persisted on foliage until the first rainfalls occurred. An empirical mathematical correlation was found to express the influence of ...

A method has been developed for the determination of the main methylated L-arginines, N G -monomethyl-L-arginine (L-NMMA), N G ,N G -dimethyl-L-arginine (symmetric dimethylarginine, L-SDMA), and N G ,N' G -dimethyl-L-arginine (asymmetric dimethylarginine, L-ADMA) in biological samples. The assay involves precolumn derivatization of methylarginines with naphthalenedicarboxaldehyde and cyanide followed by HPLC with fluorescence detection. The separation of derivatized methylated arginines on a reversed-phase column was achieved in less than 25 min. The SPE procedure developed, based on a cation-exchange resin, permits quantitative determination of analytes at concentrations as low as 0.54, 3.42, and 0.75 μg L -1 , respectively, i. e. lower than their plasma levels. Recoveries in plasma were over 81% and the inter- and intra-day relative standard deviation values as measures of repeatability were less than 4.5%. This novel and rapid method can be employed in a routine clinical setting

A solid-phase extraction method (SPE) combined with liquid chromatography with coulometric multi-electrode detection for the analysis of the main endogenous catecholamines and its metabolites in plasma samples has been developed. For this purpose, the influence of various parameters on chromatography performance, such as the pH and composition of the mobile phase, and the potentials of oxidation and reduction process, was investigated. The SPE procedure developed, following catecholamine complexation with diphenylborate, enables yields for all analytes limits of detection of 0.01–0.05 ng l−1 lower than their plasma levels. The recovery of the compounds averaged 61–99%. Relative standard deviation values for repeatability were less than 3%. This novel and rapid method can be employed in a routine clinical setting.

This article reports on the computational design, development and application of a molecularly imprinted polymer (MIP) with specific affinity towards histamine. Computational modelling was used to screen a monomer library in order to select the monomers able to form the strongest complex with the target analyte. These were subsequently used for MIP synthesis by radical polymerisation initiated by UV. MIPs were then evaluated by liquid chromatography and solid phase extraction (SPE) and best MIP behaviour was observed when itaconic acid was used as functional monomer. Finally, after optimisation of the polymer composition, MIPs were used as adsorbents for SPE and clean-up of histamine in wine samples. The proposed histamine extraction method with the MIP-SPE cartridge was found to be reproducible (5% RSD) and accurate (93-99% recovery) and provided clear wine extracts. The described methodology is simple and fast and is suitable for the selective histamine extraction and its subsequent quantification by HPLC-DAD from complex matrices such as wine samples.

The electrochemical behaviour of maltol on a glassy carbon electrode was studied. The results were applied to electrochemical detection in liquid chromatography (LC-ED). Liquid chromatography (LC) and oxidative amperometric detection with a glassy carbon electrode were used for the determination of maltol in food samples. A mobile phase of methanol-acetonitrile-citrate/phosphate buffer, pH = 2.4 (50:48:2) was used with the detector operated at E = 1000mV vs. Ag AgCl reference electrode. Under optimal conditions detection and determination limits of 0.1 and 3.7 ng respectively were obtained. The method was used for the determination of maltol in cakes. Conditions for clean-up of the sample were established using solid phase extraction cartridges.

The aim of this work was to develop a new analytical technique for the study of the organoleptic compounds (flavour profile) of the Graciano Vitis vinifera wine variety. The cv. Graciano is a singular variety of red grapes with its origins in La Rioja and Navarra (northern Spain). This variety transfers an intense red colour, aroma and high acidity to musts and provides greater longevity and, consequently, a better capacity for ageing wine. A new dual-stir bar sorptive extraction approach coupled with thermal desorption (TD) and GC–MS has been used to extract the volatile and semivolatile compounds. In this extraction step, the optimal values for the experimental variables were obtained through the Response Surface Methodology (RSM). Full scan chromatogram data were evaluated with two deconvolution software tools, and the results were compared. The volatile and semivolatile components were identified with an MS match ≥80%. As a result, the flavour metabolome of the Graciano Vitis vinifera wine variety was obtained, and 205 metabolites were identified using different databases. These metabolites were grouped into esters, acids, alcohols, nitrogen compounds, furans, lactones, ketones, aldehydes, phenols, terpenes, norisoprenoids, sulphur compounds, acetals and pyrans. The majority of the metabolites observed had already been reported in the literature; however, this work also identified new, previously unreported metabolites in red wines, which may be characteristic of the Graciano variety.

Liquid chromatographic separation prior to reductive electrochemical determination at the hanging mercury drop electrode is used to determine N -nitrosopiperidine (NPIP). A mobile phase of methanol-acetonitrile-phosphate buffer, pH 3.5 (57:38:5) is used with the detector operated in the direct current (DC) mode at E p = −1250 mV . Techniques for oxygen removal and electrochemical considerations are presented. The detection limit is 0.2 ng injected with a relative standard deviation ( n = 10) of 2.8%. The method can be applied to the determination of NPIP in beers. Conditions for the prior extraction of NPIP from beer samples have been established using solid phase extraction cartridges.

This work proposes a liquid chromatography–electrospray ionization ion trap mass spectrometry (LC–ESI-ITMS) method, for the quantification of sildenafil (SDF), tadalafil (TDF) and vardenafil (VDF) and their metabolites N-desmethylSDF, O-desethylSDF and N-desethylVDF, preceded by a sample preparation step based on protein and phospholipid elimination. A C8 column (150 mm × 4.6 mm, 5 μm) with ammonium formate (20 mM) and acetonitrile as the mobile phase components have been used. This method has been validated, obtaining limits of quantification ranged from 1 to 2.5 ng/mL and 2 to 5 ng/g in serum and brain tissue respectively, while limits of detection ranged from 0.3 to 0.9 ng/mL in serum and 0.6 to 1.9 ng/g in brain tissue. Assay recoveries for low level QC samples were higher than 83% and the matrix effect ranged between 91% and 108% in serum and between 98% and 107% in brain tissue. The method has been applied to the quantification of these compounds in the serum and brain tissue of rats treated intraperitoneally with 10 mg/kg of SDF, TDF or VDF.

A quantitative LC-MS/MS method has been developed for the simultaneous determination of 17 antipsychotic drugs in human postmortem brain tissue. Sample preparation was performed using Hybrid Solid Phase Extraction-Precipitation technology for the removal of endogenous protein and phospholipid interferences. The chromatographic separation was performed for 16 min on a C8 column, which used a gradient elution of formate ammonium and acetonitrile, and a flow rate gradient. Triple quadrupole mass spectrometry was employed to generate tandem mass spectrometric (MS/MS) data of the target analytes to select the ion m/z signals. Quantitation of the analytes was performed by operating in the dynamic multiple reaction monitoring (dMRM) mode using an electrospray ionization interface. Calibration curves prepared in the spiked brain tissue were linear in the range 20-8000 ng/g (r(2)>0.993) for all drugs (except olanzapine). Within- and between-day coefficients of variation were lower than 25% for all drugs at the LOQ. The LOQ in the matrix ranged between 2 ng/g and 80 ng/g. The method was successfully applied to the unequivocal identification and accurate quantification of antipsychotic drugs in human postmortem brain tissues: therefore, this method can be used in forensic investigations.

This paper reports the design of Molecularly Imprinted Polymers (MIP) with affinity towards (S)-citalopram using computational modeling for the selection of functional monomers and monomer:template ratio. Acrylamide was selected as functional monomer and the final complex functional monomer/template resulted in a 3:1 ratio. The polymer was synthesized by radical polymerization initiated by UV onto magnetic stir-bars in order to obtain a stir bar sorptive extraction (SBSE) device capable of selective enantiomeric recognition. After successful template removal, the parameters affecting the SBSE procedure (sample volume, ionic strength, extraction time and pH) were optimized for the effective rebinding of the target analyte. The resultant chirally imprinted polymer based stir-bar was able to selectively extract (S)-citalopram from a racemic mixture in an aqueous media with high specificity (specificity factor 4) between 25 and 500 μg L −1 . The MIP coated stir-bars can have significance for enantiospecific sample pre-concentration and subsequent analysis without the need for any chiral chromatographic separation.

A method based on sequential stir bar sorptive extraction followed by automated thermal desorption-GC-MS for the determination of pesticides in underground and superficial water samples has been developed. Retention time locked GC-MS and deconvolution Automated Mass Spectral Deconvolution and Identification System software allows the use of pesticide databases for identification and quantification in routine applications. Quantitation limits and repetitivity using full scan mass spectrometric determination guarantee the applicability of the method, which enables considerable savings to be made in total analysis time, with data processing times of around 2 min/sample.

A sensitive and specific method for determining fenitrothion and its main metabolites, 3-methyl-4-nitrophenol and fenitrooxon, in poplar leaves using deuterated isotopes as the internal standard is described. The analytes and the labeled isotopes were extracted from leaves by solid-phase microextraction and subsequently analysed by gas chromatography coupled with mass spectrometry. The method had a chromatographic run time of 17.0 min and good linearity over the range 0.01-10 mg kg(-1). The detection limits ranged between 2.5 and 0.6 microg kg(-1). The isotopic dilution technique allowed improving significantly the repetitivity even using different fibers with the same coating (RSD5.1%). The method was applied successfully to study the persistence of fenitrothion in forestal matrices in a poplar forest after cannon spray application of the insecticide.

A liquid chromatography method was developed for the determination of some frequently prescribed selective serotonin re-uptake inhibitors (SSRI) - citalopram and fluoxetine - and its main metabolites - demethylcitalopram, didemethylcitalopram and norfluoxetine - in human urine samples, using a previous stage of solid-phase microextraction. All the extraction parameters influencing adsorption (extraction time, temperature, pH, ion strength and organic modifier addition) and desorption (desorption time and desorption solvent mixture composition) of the analytes on the fiber have been studied. A satisfactory reproducibility for extraction from urine samples (R.S.D.10%) was obtained. The linearity for urine ranged from 0.05 to 2 mg l(-1) with limits of detection close to 0.01 mg l(-1), which cover the typical urinary concentrations obtained for citalopram, fluoxetine and their metabolites.

A rapid liquid chromatographic-electrospray ionisation ion trap mass spectrometry (LC-ESI-ITMS) method has been developed for the routine analysis of eight of the most oenologically important biogenic amines in wine without any sample pre-treatment. The method involves addition of heptylamine as an internal standard (IS) and the direct injection of filtered wine samples previously diluted with ultra high purity (UHP) water. The full-scan MS-MS spectra and the identical retention times to those of reference standards were used for unequivocal identification of the analytes. For most amines, the most abundant ions were derived from the loss of an ammonia group, while in the case of spermine and the I.S. the major product ions arose from the loss of 1,3-propyldiamine and the production of adduct with water, respectively. Detection was achieved in positive ionisation with an ion trap mass spectrometer operating in multiple-reaction monitoring (MRM) mode. The method allowed accurate determination of the analytes in the range 0.5-40 ng mL(-1). Within-day and between-day relative standard deviation percentages were