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In this study, Amberlite CG-120 adsorbent was used for the separation/preconcentration of Ni(II) ions in commercial drinking, spring and lake water samples before detection by flame atomic absorption spectrometry. Various optimization parameters for Ni(II) determination, such as pH, eluent type and concentration, sample and eluent flow rates, amount of adsorbent, were investigated to obtain better sensitivity, accuracy, precision and quantitative recovery. Furthermore, the interference effects of some ions on the recovery efficiency of Ni(II) were also investigated. The optimum experimental parameters were obtained in the case of pH 1; 5 mL of 4 mol L -1 HCl for eluent and 0.3 g for the adsorbent amount. The limit of detection was found to be 0.58 μg L -1 and linearity ranged from 5 to 50 μg L -1 . The accuracy of the method was tested by the certified reference material of TMDA-70.2 Ontario Lake Water at a 95% confidence level.

Plasma is a rich source of biomarkers with clinical relevance. However, the wide dynamic range of protein concentration hinders the detection of low abundance proteins. Plasma prefractionation methods serve as indispensable tools to reduce plasma complexity, allowing the opportunity to explore tissue-derived proteins which leak into the circulation. This review summarizes common approaches in plasma prefractionation methods for proteomic analysis and then discusses some considerations in plasma prefractionation for clinical applications, reviewing some examples of its use in clinical situations., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The objective of this research was to utilize the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method to extract a broad range of persistent organic pollutants from sturgeon organs (liver and gonad) as indicators of exposure. The analyte list was prioritized to include carcinogenic polyaromatic hydrocarbons (PAHs), the most commonly occurring polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), persistent bioaccumulative and toxic chemicals (PBTs), and emergent contaminants of concern (ECCs) as indicators of human sewage exposure. White sturgeon (Acipenser transmontanus) were selected for this study to support a larger ecotoxicological study to monitor contaminants as an assessment of fish health. Organ tissues contained high lipid content with percentages of 15% and 34% for liver and gonad, respectively. Overall recoveries from fortified sturgeon tissues were high, 71-98% for PAHs, 60-107% for PBDEs and PCBs, 86-107% for PBT chemicals, and 88-107% for ECCs with the exception of octinoxate (28%) from liver tissues. Analyte recovery trends decreased as analyte lipophilicity and molecular weight increased. These recoveries demonstrate that extraction using QuEChERS can be used for screening of the most common bioaccumulating organic compounds in high lipid fish tissue using a single extraction and analysis., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Online and automated sample extraction is widely used to increase the throughput and improve the quality of LC-MS/MS analysis. In this article, we review the most commonly used online sample extraction methodologies including online SPE, turbulent flow chromatography, online DBS extraction and online immunoaffinity extraction. We also review the offline automated sample extraction platforms, including custom robot scripts for the automation of individual steps during sample extraction, the robot scripts for the automation of individual assays, and the platform for integrated multiple sample extraction. The most recent developments and future trends in this area are also discussed.

This special report discusses the sample preparation method electromembrane extraction, which was introduced in 2006 as a rapid and selective miniaturized extraction method. The extraction principle is based on isolation of charged analytes extracted from an aqueous sample, across a thin film of organic solvent, and into an aqueous receiver solution. The extraction is promoted by application of an electrical field, causing electrokinetic migration of the charged analytes. The method has shown to perform excellent clean-up and selectivity from complicated aqueous matrices like biological fluids. Technical aspects of electromembrane extraction, important extraction parameters as well as a handful of examples of applications from different biological samples and bioanalytical areas are discussed in the paper.

Urine has garnered tremendous interest over the past decade as a potential source of protein biomarkers for various pathologies. However, due to its low protein concentration and the presence of interfering compounds, urine constitutes a challenging analyte in proteomics. In the context of a project aimed at the discovery and evaluation of new candidate biomarkers of bladder cancer in urine, our laboratory has implemented and evaluated an array of preparation techniques for urinary proteome analysis. We present here the protocol that, in our hands, yielded the best overall proteome coverage with the lowest analytical effort. It begins with protein precipitation using trichloroacetic acid, in solution digestion and RP-C18 cartridge desalting of the resulting peptides mixture, and is followed by peptide fractionation by gel-free isoelectric focusing, and nano-LC-MS/MS for database compilation.

Sample preparation is important in obtaining accurate data for qualification and quantification in bioanalysis. We have recently focused on monolithic silica for high-throughput analysis. These extraction processes - using monolithic silica packed in spin column - such as sample loading, washing and elution, are executed by centrifugation. There are several possibilities such as on-column derivatization for the determination of amines or carboxylic acids in the sample. The spin column extraction reduces the sample preparation time required for determination of drugs and other chemicals in biological materials and increases productivity in bioanalysis. We expect spin column extraction to become the mainstream method of sample processing in the future.

Stir bar sorptive extraction (SBSE) is a sample preparation technique, which is used for the extraction as well as the preconcentration of organic substances from various aqueous matrices, prior to the determination of the analytes with a separation technique, such as LC or GC, coupled to different detectors. Since 1999, when SBSE was first developed by Sandra and co-workers, SBSE has been used in the analysis of samples of environmental, food, pharmaceutical and biomedical origin. In this article, we focus on the application of SBSE in biological fluids.

Hg concentrations in seawater are usually too low to allow direct (without pre-concentration and removal of salt matrix) measurement of its isotope ratios with multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). Therefore, a new method for the pre-concentration of Hg from large volumes of seawater was developed. The final method allows for relatively fast (about 2.5Lh(-1)) and quantitative pre-concentration of Hg from seawater samples with an average Hg recovery of 98±6%. Using this newly developed method we determined Hg isotope ratios in seawater. Reference seawater samples were compared to samples potentially impacted by anthropogenic activity. The results show negative mass dependent fractionation relative to the NIST 3133 Hg standard with δ(202)Hg values in the range from -0.50‰ to -1.50‰. In addition, positive mass independent fractionation of (200)Hg was observed for samples from reference sites, while impacted sites did not show significant Δ(200)Hg values. Although the influence of the impacted sediments is limited to the seawater and particulate matter in very close proximity to the sediment, this observation may raise the possibility of using Δ(200)Hg to distinguish between samples from impacted and reference sites., (Copyright © 2014 Elsevier B.V. All rights reserved.)

One of the present trends in analytical chemistry is miniaturization, which is one of the methods of green analytical chemistry application. A particular emphasis is placed on the elimination of the use of large amounts of organic solvents which are toxic and harmful to the environment, maintaining high efficiency of the extraction process, high recovery values and low values of quantification (LOQ) and detection (LOD) limits. These requirements are fulfilled by coacervative extraction (CAE) technique. In this review, theoretical aspects of the coacervation process are presented along with environmental and bioanalytical applications of this technique, its advantages, limitations and competitiveness with other techniques. Due to its simplicity and rapidity, CAE is an excellent alternative for currently practiced procedures of sample preparation for the analysis of organic compounds., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The nano-mediated preconcentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin from blood samples was reported by inclusion-facilitated emulsion liquid membrane process. The novelty of this study was application of nano-baskets of calixarene and emulsion liquid membranes in selective and efficient preconcentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin. For this aim, four derivatives of p-tert-calix[4]arene bearing different sulfonamide moieties were synthesized and their inclusion-extraction parameters were optimized including calixarenes' scaffold and concentration (3, 4 wt%), diluent type in membrane, phase and treat ratios (0.8 and 0.3), mixing speed (300 rpm), and initial solute concentrations (0.1-10 pg g(-1)). The extraction efficiency was determined by dioxin's concentration using gas chromatography equipped with electron capture detector and the results revealed that in optimized operating conditions, the preconcentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin was improved and the limit of detection decreased., (Copyright © 2012 Elsevier B.V. All rights reserved.)

This review covers recent developments in sample preparations and analytical techniques for determination of residues of carbamate pesticides. Special attention is paid to the newly established microextraction techniques, including cloud-point extraction, dispersive liquid-liquid microextraction, and ultrasound-assisted surfactant-enhanced emulsification microextraction. In addition, extractions using a variety of solvents, as well as miniaturized and on-line sample preparation systems, are discussed. Applications of the different methods for the determination of carbamate pesticide residues in food and environmental matrices are included., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A rapid and simple extraction technique based on aqueous two-phase system (ATPS) was developed for separation and enrichment of vitamin B(12) in urine samples. The proposed ATPS-based method involves the application of the hydrophilic ionic liquid (IL) 1-hexyl-3-methylimidazolium chloride and K(2)HPO(4). After the extraction procedure, the vitamin B(12)-enriched IL upper phase was directly injected into the high performance liquid chromatography (HPLC) system for analysis. All variables influencing the IL-based ATPS approach (e.g., the composition of ATPS, pH and temperature values) were evaluated. The average extraction efficiency was 97% under optimum conditions. Only 5.0 mL of sample and a single hydrolysis/deproteinization/extraction step were required, followed by direct injection of the IL-rich upper phase into HPLC system for vitamin B(12) determination. A detection limit of 0.09 μg mL(-1), a relative standard deviation (RSD) of 4.50% (n=10) and a linear range of 0.40-8.00 μg mL(-1) were obtained. The proposed green analytical procedure was satisfactorily applied to the analysis of samples with highly complex matrices, such as urine. Finally, the IL-ATPS technique could be considered as an efficient tool for the water-soluble vitamin B(12) extraction., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Several new products have been marketed with the specific capability of removing phospholipids. These products were evaluated alongside more traditional extraction techniques, using UHPLC and precursor-ion scanning (pre m/z 184), which detects glycerophosphocholines (GPCho), lyso-GPCho and sphingomyelins. Using this technique the plasma GPCho profile of human, dog and rat plasma is briefly compared., Results: Precursor-ion scanning detected more of the phospholipid profile in extracts than a SRM experiment (m/z 184-184). Products designed for the purpose were the most efficient at removing phospholipids and reversed-phase SPE was better than mixed-mode cation exchange. A comparison of different UHPLC columns demonstrated that C(8) or phenyl phases would help manage the elution of GPChos., Conclusion: Phospholipid removal plates are useful where no sample concentration is required; however for more challenging LOD it will be necessary to enrich the original sample. In these cases build-up of phospholipids can be avoided with a thoughtful choice of UHPLC column.

Difference gel electrophoresis (DIGE) (Electrophoresis 18, 2071-2077, 1997, 1) is widely used in cardiovascular research. However, the dynamic range limitations stemming from contaminating plasma proteins and highly abundant extracellular matrix components can make cardiovascular tissues difficult to analyze. Here we describe a novel methodology for biochemical subfractionation of cardiovascular tissues before DIGE analysis.

A novel sample preparation technique, the microextraction method based on a dynamic single drop in a narrow-bore tube, coupled with gas chromatography-flame ionization detection (GC-FID) is presented in this paper. The most important features of this method are simplicity and high enrichment factors. In this method, a microdrop of an extraction solvent assisted by an air bubble was repeatedly passed through a narrow-bore closed end tube containing aqueous sample. It has been successfully used for the analysis of some pesticides as model analytes in aqueous samples. Parameters affecting the method's performance such as selection of extraction solvent type and volume, number of extractions, volume of aqueous sample (tube length), and salt effect were studied and optimized. Under the optimal conditions, the enrichment factors (EFs) for triazole pesticides were in the range of 141-214 and the limits of detection (LODs) were between 2 and 112 μg L(-1). The relative standard deviations (C=1000 μg L(-1), n=6) were obtained in the range of 2.9-4.5%. The recoveries obtained for the spiked well water and grape juice samples were between 71 and 106%. Low cost, relatively short sample preparation time and less solvent consumption are other advantages of the proposed method., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Stir bar sorptive extraction (SBSE) is an environmentally-friendly technology of sample preparation which combines extraction, cleanup and enrichment together, and it has been developed rapidly and widely applied to the trace enrichment of various target analytes in environmental, food and biological samples. Based on our research, the advance of SBSE, especially, the development of new coatings, are reviewed. At the same time, the possible development orientations of SBSE are discussed.

Bioanalysis usually requires a preparation procedure for sample cleanup or preconcentration. Conventional sample preparation techniques are often time consuming and labor intensive. Among recent progress in sample preparation, single drop microextraction (SDME) is one of the most efficient techniques providing both sample cleanup and preconcentration capabilities. In SDME, analytes are extracted from a sample solution into an acceptor drop and the drop is introduced to subsequent analysis. Since the volume of the acceptor drop is 1-10 µl or less, the consumption of solvents can be minimized and the preconcentration effect is enhanced. In this review, the basic principles of two-phase and three-phase SDME are described briefly and then recently developed modes of SDME, coupling with analytical instruments, and methods to enhance the drop stability are discussed. Recent applications of SDME to biological samples, including urine, blood and saliva, for the analysis of drugs, metal ions and biomarkers are reviewed.

A new method based on microcolumn packed with ionic liquid-modified silica combined with flame atomic absorption spectrometry has been developed for the determination of lead in environmental samples. Several factors influencing the preconcentration efficiency of lead and its subsequent determination, such as pH of the sample, flow rate, mass of ionic liquid, and interfering effect, have been investigated. Lead could be quantitatively retained by ionic liquid-modified silica in the pH range of 5-7, and then eluted completely with 3.0 mL 1.0 mol L(-1) HCl. The detection limit of this method for lead was 0.7 μg L(-1) with preconcentration factor of 185, and the relative standard deviation (RSD) was 4.2% at 0.1 μg mL(-1) Pb(II). This method has been applied for the determination of trace amount of lead in NIST standard reference material 2709 (San Joaquin Soil) and river water samples with satisfactory results., (Copyright © 2011. Published by Elsevier B.V.)

An analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS-MS) was developed for the determination of rhamnolipids. A dispersive liquid-liquid microextraction (DLLME) procedure was used to isolate and concentrate target compounds from aqueous samples collected from surface water, sewage treatment plant effluent and cultivation of microbial culture. Development of the DLLME procedure included optimization of several important parameters such as kind and volume of extracting and dispersing solvents as well as sample pH. Under optimized conditions a two-step extraction with sonication was used. Chloroform was applied as the extracting and acetone as the dispersing solvent. The recoveries of the analytes were 70-87%. Matrix effects investigated for the analytes revealed existence of ionization enhancement for both mono- and dirhamnolipids., (Copyright © 2010 Elsevier B.V. All rights reserved.)

In most diseases, the clinical need for serum/plasma markers has never been so crucial, not only for diagnosis, but also for the selection of the most efficient therapies, as well as exclusion of ineffective or toxic treatment. Due to the high sample complexity, prefractionation is essential for exploring the deep proteome and finding specific markers. In this study, three different sample preparation methods (i.e., highly abundant protein precipitation, restricted access materials (RAM) combined with IMAC chromatography and peptide ligand affinity beads) were investigated in order to select the best fractionation step for further differential proteomic experiments focusing on the LMW proteome (MW inferior to 40,000 Da). Indeed, the aim was not to cover the entire plasma/serum proteome, but to enrich potentially interesting tissue leakage proteins. These three methods were evaluated on their reproducibility, on the SELDI-TOF-MS peptide/protein peaks generated after fractionation and on the information supplied. The studied methods appeared to give complementary information and presented good reproducibility (below 20%). Peptide ligand affinity beads were found to provide efficient depletion of HMW proteins and peak enrichment in protein/peptide profiles., (Copyright 2010 Elsevier B.V. All rights reserved.)

Background: A novel approach for regulated bioanalytical sample preparation has been developed to combine multiple types of extraction techniques into one integrated and automated sample-preparation suite that pairs a graphical user interface with the Hamilton Microlab(®) STAR robotic liquid handler., Results: The multi-assay sample-preparation suite is composed of three bioanalytical extraction techniques: protein precipitation, solid-phase extraction and liquid-liquid extraction. Validation data provided highly reproducible and robust results for each respective automated extraction technique., Conclusion: The user-friendly graphical user interface and modular method design provide a flexible and versatile approach for routine bioanalytical sample-preparation and is the first fully integrated multiple assay sample-preparation suite for regulated bioanalysis.

A novel method of ultrasonic probe-assisted ionic liquid dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry (ETAAS) was developed for the determination of chromium(VI) species in water samples. In this procedure, the hydrophobic chelate of chromium(VI) with ammonium pyrrolidinedithiocarbamate (APDC) was extracted into the fine droplets of 1-hexyl-3-methylimidazolium hexafluorophosphate ([Hmim][PF(6)]), which was dispersed into the aqueous sample solution by ultrasonication using an ultrasonic probe. Several variables such as the volume of [Hmim][PF(6)], sample pH, concentration of APDC, and extraction time were investigated in detail. Under the optimum conditions, the limit of detection of the proposed method was 0.07 ng mL(-1) for Cr(VI) and the relative standard deviation for five-replicated determination of 2.0 ng mL(-1) Cr(VI) was 9.2%. The proposed method has been also successfully applied to the determination of chromium(VI) species in lake and tap water samples., ((c) 2009 Elsevier B.V. All rights reserved.)

Functional metabolomics of skeletal muscle involves the simultaneous identification and quantification of a large number of metabolites. For this purpose, the extraction of metabolites from animal tissues is a crucial technical step that needs to be optimized. In this work, five extraction methods for skeletal muscle metabolome analysis using liquid chromatography tandem mass spectrometry (LC-MS/MS) were tested. Bird skeletal muscles sampled postmortem and quenched in liquid nitrogen were used. Three replicates of the same sample were extracted using the following solvent systems of varying polarity: boiling water (BW, +100 degrees C), cold pure methanol (CPM, -80 degrees C), methanol/chloroform/water (MCW, -20 degrees C), boiling ethanol (BE, +80 degrees C), and perchloric acid (PCA, -20 degrees C). Three injections by extraction were performed. The BW extraction showed the highest recovery of metabolites with the lowest variability (<10%) except for creatine-phosphate (creatine-P). Considering yield (area of the peaks), reproducibility, and ease, the current experiment drew a scale for the muscle metabolome extraction starting from the best to the least convenient: BW>MCW>CPM>PCABE. In addition, the semiquantification of metabolites in two muscles showing different metabolic and contractile properties was carried out after BW extraction and showed expected differences in metabolite contents, thereby validating the technique for biological investigations. In conclusion, the BW extraction is recommended for analysis of skeletal muscle metabolome except for creatine-P, which was poorly recovered with this technique., (Copyright (c) 2009 Elsevier Inc. All rights reserved.)

Background: Microextraction by packed sorbent (MEPS) is used as an online sample-preparation method. The determination of local anesthetics lidocaine, ropivacaine and bupivacaine directly in human blood was performed using MEPS online with LC-MS/MS., Results: The range of the calibration curves in whole blood was 10-10000 nmol/l. The lower limit of quantification was set to 10.0 nmol/l. The accuracy of the quality control samples ranged from 85 to 97%. The interday precision of the studied analytes was within the range 1-5%. The regression correlation coefficient (r(2)) was over 0.995 for all runs. The present method is rapid, reliable and robust and may be used for therapeutic drug monitoring of studied analytes in whole blood., Conclusion: This assay allows the analysis of drugs in human blood directly. Sample preparation is simple and automated. The assay reduced the handling time and the cost, and could handle small volumes of whole blood samples (25 µl).

Partitioned dispersive liquid-liquid microextraction (PDLLME), using THF as the dispersive solvent and dichloromethane as the extraction solvent, was utilized to isolate and concentrate phenylurea herbicides (PUHs) from aqueous samples. In PDLLME, a dispersive solvent should be able to partition in the organic extractant droplets to effectively extract the polar organic compounds from aqueous samples. The mixture of the water-immiscible extractant and the partitioned dispersive solvent was obtained by centrifugation, dried under low pressure, reconstituted in methanol-water mixture (1:1), and injected into a HPLC system for the determination of PUHs. The enrichment factors of the PUHs ranged from 68 to 126 under the optimal conditions. The linear range was 0.5-100 ng ml(-1) for each analyte, the relative standard deviations of PUHs were in the range of 1.5-5.9% (n=5), and the detection limits (signal-to-noise ratio of 3) ranged from 0.10 to 0.28 ng ml(-1) for the herbicides. The range of intraday precision (n=5) for PUHs at the levels of 0.5, 5, and 50 ng ml(-1) were 3.0-5.9%, 1.8-3.3%, and 2.2-3.6%, respectively. The range of interday precision (n=5) at 0.5, 5, and 50 ng ml(-1) were 0.4-1.8%, 1.2-2.4%, and 0.9-2.3%, respectively. The recoveries of PUHs from three spiked river water samples, at a level of 10 ng ml(-1), were 91.2-104.1%. Due to its rapidity, ease of operation, and high recovery, PDLLME can be utilized to isolate and concentrate organic environmental contaminants such as PUHs from aqueous samples.

The present study has for the first time demonstrated the isolation of peptides from human plasma by electromembrane extraction (EME). Angiotensin 1, angiotensin 2, and angiotensin 3 migrated from 500 microL of diluted plasma, through a thin layer of 1-octanol and 8% di-(2-ethylhexyl) phosphate immobilized as a supported liquid membrane (SLM) in the pores of a porous hollow fiber, and into a 25 microL aqueous acceptor solution present inside the lumen of the fiber. The driving force for the extraction was a 15 V potential difference applied across the SLM. After only 10 min of EME, the peptides were isolated from diluted plasma (pH 3) with extraction recoveries between 25 and 43%. After optimization, the extraction system was evaluated using spiked plasma samples of angiotensin 2. The evaluation was performed by liquid chromatography electrospray mass spectrometry, showing linearity of angiotensin 2 in the range 2.5-125.0 ng/mL (r(2)=0.989), and repeatability (RSD) between 5.6 and 11.6% (n=6). The results demonstrate the possibility of isolating angiotensin peptides from plasma in only 10 min, using electromembrane extraction. The experimental findings are therefore promising with regard to future peptide extractions.

Sample preparation before chromatographic separation is the most time-consuming and error-prone part of the analytical procedure. Therefore, selecting and optimizing an appropriate sample preparation scheme is a key factor in the final success of the analysis, and the judicious choice of an appropriate procedure greatly influences the reliability and accuracy of a given analysis. The main objective of this review is to critically evaluate the applicability, disadvantages, and advantages of various sample preparation techniques. Particular emphasis is placed on extraction techniques suitable for both liquid and solid samples.

This review article deals with molecularly imprinted polymers (MIPs) as affinity-based separation media for sample preparation. An over view of two types of MIPs (molecularly imprinted particle and monolith) used for the sample preparation and modes of molecularly imprinted SPE (online mode, offline mode, on-column extraction, SPME, and microextraction in packed syringe) is given, focusing on the advantages and disadvantages of these types and modes. Next, problems (template leakage and incompatibility with aqueous conditions) associated with molecularly imprinted SPE and how to overcome those problems are described. Finally, pharmaceutical, food, bioanalytical, and environmental application of molecularly imprinted SPE will be discussed.

A rapid and sensitive method for the determination of carbendazim (methyl benzimidazole-2-ylcarbamate, MBC) and thiabendazole (TBZ) in water and soil samples was developed by using dispersive liquid-liquid microextraction (DLLME) coupled with high performance liquid chromatography with fluorescence detection. The water samples were directly used for the DLLME extraction. For soil samples, the target analytes were first extracted by 0.1 mol L(-1) HCl. Then, the pH of the extract was adjusted to 7.0 with 2 mol L(-1) NaOH before the DLLME extraction. In the DLLME extraction method, chloroform (CHCl(3)) was used as extraction solvent and tetrahydrofuran (THF) as dispersive solvent. Under the optimum conditions, the enrichment factors for MBC and TBZ were ranged between 149 and 210, and the extraction recoveries were between 50.8 and 70.9%, respectively. The linearity of the method was obtained in the range of 5-800 ng mL(-1) for water sample analysis, and 10-1000 ng g(-1) for soil samples, respectively. The correlation coefficients (r) ranged from 0.9987 to 0.9997. The limits of detection were 0.5-1.0 ng mL(-1) for water samples, and 1.0-1.6 ng g(-1) for soil samples. The relative standard deviations (RSDs) varied from 3.5 to 6.8% (n=5). The recoveries of the method for MBC and TBZ from water samples at spiking levels of 5 and 20 ng mL(-1) were 84.0-94.0% and 86.0-92.5%, respectively. The recoveries for soil samples at spiking levels of 10 and 100 ng g(-1) varied between 82.0 and 93.4%.

Sample preparation and fractionation technologies are one of the most crucial processes in proteomic analysis and biomarker discovery in solubilized samples. Chromatographic or electrophoretic proteomic technologies are also available for separation of cellular protein components. There are, however, considerable limitations in currently available proteomic technologies as none of them allows for the analysis of the entire proteome in a simple step because of the large number of peptides, and because of the wide concentration dynamic range of the proteome in clinical blood samples. The results of any undertaken experiment depend on the condition of the starting material. Therefore, proper experimental design and pertinent sample preparation is essential to obtain meaningful results, particularly in comparative clinical proteomics in which one is looking for minor differences between experimental (diseased) and control (nondiseased) samples. This review discusses problems associated with general and specialized strategies of sample preparation and fractionation, dealing with samples that are solution or suspension, in a frozen tissue state, or formalin-preserved tissue archival samples, and illustrates how sample processing might influence detection with mass spectrometric techniques. Strategies that dramatically improve the potential for cancer biomarker discovery in minimally invasive, blood-collected human samples are also presented.

In present time the use or misuse of morphine and its derivatives are monitored by assaying the presence of the drug and its metabolites in biofluids. In the present review, focus is placed on the sample preparation and on the separation techniques used in the current best practices of bioanalysis of morphine and its major metabolites. However, as methods for testing the misuse of heroin, a morphine derivative, often involve bioanalytical methods that cover a number of other illicit drug substances, such methods are also included in the review. Furthermore, the review also includes bioanalysis in a broader perspective as analysis of plant materials, cell cultures and environmental samples. The review is not intended to cover all publications that include bioanalysis of morphine but is more to be considered a view into the current best practices of bioanalysis of morphine, its metabolites and other related substances.

The use of electrochemistry and electrical behavior as a control and manipulation factor in analyte extractions is reviewed. Electromodulated extractions of ionic and neutral analytes are possible using this general approach. Extractions based on solid-liquid, liquid-liquid and membrane behaviors have been demonstrated and reported together with analyte extractions from real matrices and interfacing with instrumental detection methods. The electromodulation strategy offers great opportunities for selectivity in sample preparation.

The most recent contributions on solventless extraction techniques have been reviewed. This paper deals with those techniques that use solid phases, such as solid-phase microextraction, liquid phases, such as single-drop microextraction and hollow-fibre liquid-phase microextraction, and subcritical fluids, such as subcritical water extraction. In all cases, the most recent publications have been critically studied. Direct extraction and derivatization processes to facilitate the extraction of analytes in different areas have been included. Hyphenated approaches, if available, are also included in this review. Comparison of techniques organized by analytes and matrices also enhances this critical overview of solventless techniques.

Partitioned dispersive liquid-liquid microextraction (PDLLME) efficiency was demonstrated for the extraction of polar organic compounds (chlorophenoxyacetic acids) prior to high performance liquid chromatography (HPLC). The method was based on the formation of tiny droplets of an organic extractant in an aqueous sample (river water) by injecting a mixture of a water-immiscible organic solvent [tetrachloroethylene (TCE)] as extractant dissolved in a water-miscible organic dispersive solvent [tetrahydrofuran (THF)]. Based on their partition coefficients, polar compounds were extracted into the dispersed TCE droplets as well as into THF. Different parameters affecting the extraction efficiency were evaluated and precision, linearity, detection limit and an enrichment factor were determined.