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Biguanides are nitrogen containing compounds and classified as antidiabetic (metformin, phenformin, buformin), antimalarial (proguanil, cycloproguanil, 4-chlorophenyl biguanide), and antimicrobial (chlorhexidine, polyhexamethylene biguanide) drugs. These biguanides provide safe medication and are used worldwide. Therefore, various effective analytical procedures for quality control and pharmacodynamics and pharmacokinetic studies have been developed. However, HPLC method is a technique in great demand due to its attractive features and availability of the stationary and mobile phases. This article highlights the role of HPLC for the determination of biguanides and related compounds in different biological and environment samples. The sample preparation is a bottleneck of analytical procedure, which involves the isolation or extraction of the desired analytes from the sample matrix as these are present at trace level. The application of various solid phase extraction (SPE) materials used for the sample preparation of biguanides are also discussed herein. [ABSTRACT FROM AUTHOR]

Acrylamide (AA) is a compound classified as carcinogenic to humans by the International Agency for Research on Cancer. It was first discovered to be present in certain heated processed food by the Swedish National Food Administration (SNFA) and University of Stockholm in early 2002. The major pathway for AA formation in food is the Maillard reaction between reducing sugar and the amino acid asparagine at high temperature. Since the discovery of AA's presence in food, many analytical methods have been developed for determination of AA contents in different food matrices. Also, several studies have been conducted to develop extraction procedures for AA from difficult food matrices. AA is a small, highly polar molecule, which makes its extraction and analysis challenging. Many articles and reviews have been published dealing with AA in food. The aim of the review is to discuss AA formation in food, the factors affecting AA formation and removal, AA exposure assessment, AA extraction and cleanup from food samples, and analytical methods used in AA determination, such as high-performance liquid chromatography (HPLC) and gas chromatography (GC). Special attention is given to sample extraction and cleanup procedures and analytical techniques used for AA determination. [ABSTRACT FROM PUBLISHER]

The enantiomers of chiral drugs (CDs) can have different pharmaceutical properties and biological activities in the presence of other biomolecules. The molecular recognition of chiral drugs is an important issue in the pharmaceutical field. Capillary electrophoresis (CE) plays a critical role in enantiomer discrimination. Molecular modeling is a powerful tool to study enantioseparation in addition to experimental methods such as CE. Many molecular modeling studies have been performed to investigate CD inclusion complexes aimed at comprehending the mechanism of the complexation and correlating the experimental results with the mode of the interaction between a CD host and a guest molecule. This review illustrates the contribution of chiral capillary electrophoresis in combination with molecular modeling to a better understanding of the chiral recognition mechanisms with CDs as chiral selectors. [ABSTRACT FROM AUTHOR]

Differential spectroscopy is an elegant and powerful analytical method, based on the relatively simple principles of classical absorption spectroscopy. Some background to differential spectroscopy as well as an updated applications in the period 2000–2013 are reviewed. Associated with chemometrics, it can become a powerful tool for the pharmaceutical industry. Indeed, it is suitable for analysis of solid, liquid, and biotechnological pharmaceutical forms. This review focuses on applications used for qualitative and quantitative analysis. Moreover, it can be implemented during pharmaceutical development, in production for process monitoring, and in quality control laboratories. [ABSTRACT FROM AUTHOR]

A new method was developed to determine the contents of PAHs in fish by gas chromatography–triple quadrupole mass spectrometry (GC–QqQ-MS/MS) with SRM mode. In this method, ultrasonic extraction with hexane/dichloromethane (1:1v/v) and Florisil column cleaning with hexane/acetone (4:1v/v) was used as the sample pretreatment. Recoveries of the 16 PAHs for spiked samples were between 68.5% and 106.3%, the relative standard deviations (RSD) were between 0.1% and 17.8%. The limits of detection (LODs) ranged from 0.024–0.06 μg/kg and the limits of quantitation (LOQs) ranged from 0.08–0.2 μg/kg. The influence of different elution solvent to recovery and the matrix effect were also discussed. [ABSTRACT FROM PUBLISHER]

A multiresidue method using gas chromatography with electron-capture detection (ECD), nitrogen-phosphorus detection (NPD), or flame ionization detection (FID) has been developed for the determination of triazole residues such as triadimefon, penconazole, hexaconazole, diniconazole, and organophosphorus residues such as chlorpyrifos-methyl. The method has been successfully applied to the analysis of tomatoes and eggplant samples. The recoveries obtained from NPD detector for tomatoes and eggplants were in the range 62.0–109% and 66.0–104% with the relative standard deviation varied from 5.0 to 13.1% and 3.2 to 18.0%, respectively. The method was validated and applied for the determination of triazole and organophosphorus pesticides in agrochemical formulations within the recoveries of 96.3–107.2%. [ABSTRACT FROM AUTHOR]

Sildenafil citrate (SC) is a commonly used pharmaceutical compound in the treatment of erectile dysfunction. Many side effects were reported for overdose including: headaches; fainting resulting from dilation of blood vessels, and blue-tinted vision. Many analytical methods are reported in literature for the assay of sildenafil citrate in its generic form or pharmaceutical formulations; these will be summarized in the present mini review. [ABSTRACT FROM AUTHOR]

An electrochemical polyvinyl chloride membrane sensor for sertraline (Ser) was prepared based on the ion associate of sertraline with phosphotungstic acid. The sensor was fully characterized in terms of its membrane composition, life span, effect of soaking, pH, interferences, and temperature and exhibited an average Nernestian response (61.6 ± 0.9 mV/decade) in the concentration range of 1.0 × 10-2 -5.0 × 10-5 M. Sertraline was assayed potentiometrically in its pure solutions and pharmaceutical preparations using the developed electrode under batch and flow injection conditions and the recovery values ranged from 93.44-101.12%, with a relative standard deviation of 0.53-1.27%. The sensor was successfully applied to the determination of the dissolution profile study of (Ser) tablets and the results were validated by comparison with spectrophotometric assays according to the quality control unit of the tablets pharmaceutical company producers. The results obtained from the proposed electrode were statistically analyzed and compared to a reported method. No significant difference was observed regarding both accuracy and precision. [ABSTRACT FROM AUTHOR]

A high pressure liquid chromatography-diode array detector (HPLC-DAD) method using amylose tris(3,5-dimethylphenyl carbamate) chiral stationary phase (Chiralpak AD-H) is described for the determination of doxylamine enantiomers in human plasma. Doxylamine enantiomers were separated on a Chiralpak AD-H column using a mobile phase composed of n-hexane-2-propanol-diethylamine (98:2:0.025, v/v/v). Diphenhydramine was used as an internal Standard (IS). Doxylamine was extracted from plasma samples using dichloromethane:hexane (1:2 v/v), which yielded high extraction yields (87%), satisfactory precision (RSD < 1.05%), and good selectivity. Linearity was found in the 8-40 µg · mL-1 range with the limits of detection 0.13 µg · mL-1. Doxylamine enantiomers were well separated with no interference from endogenous plasma constituents. The method developed, showed a good linearity, sensitivity, and repeatability. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of cyromazine (N-cyclopropyl-1,3,5-triazine-2,4,6 triamine) insecticide has been studied at newly prepared multi-wall carbon nanotubes paste electrodes using square wave stripping voltammetry. The cyromazine was accumulated at 0.0 mV [vs. Ag/AgCl (3 M NaCl)] and a well-defined anodic peak obtained at +1110 mV in 0.1 M H2SO4. The cyclic voltammetric measurements showed an irreversible nature of oxidation wave in the range of scan rates comprised between 500 and 4000 mV s-1. The calibration curve obtained from square wave stripping voltammetry was linear in the range 0.41 to 83.30 µg/mL with a detection limit of 0.12 µg/mL. The method was applied to the direct determination of cyromazine in natural water samples. Recoveries calculated for river and tap water samples spiked with 10.0 µg/mL level were 101.5 ± 1.9% and 100.6 ± 2.3% at 95% confidence level, respectively. The method was extended to the determination of cyromazine in agrochemical formulation Trigard® with a recovery of 100.49% and accuracy was in agreement with that obtained by HPLC comparison method. Influences of some interfering ions and pesticides were also investigated. [ABSTRACT FROM AUTHOR]

The heavy metal content was investigated for six mushroom species native to Jordan. Metal (Cu, Pb, Cd, Fe, Zn, Mn, Ni, and Co) content in soil substrate and their relation to metal concentrations in mushroom and underlying soil were determined by flame and graphite furnace atomic absorption spectrometry. Mushroom species and soil were collected from different places in Jordan. The highest Cu level was 51.84 µg g-1 for the species Lepista nuda; whereas, the lowest Cu level was found to be 18.51 µg g-1 in Calvatia utriformis. Among the wild mushrooms, the highest Pb level was found as 4.81 µg g-1 in Bovista plumbea, whereas the lowest Pb concentration was 2.01 µg g-1 in Calvatia utriformis. The highest Cd level was determined as 1.9 µg g-1 for Lepista nuda, whereas the lowest Cd level was 0.58 µg g-1 for the species of Polyporus frondosus. The highest Zn level was 58.77 µg g-1 for the species of Lepista nuda and the lowest Zn concentration was found 35.98 µg g-1 in Calvatia utriformis. The highest Fe level was found as 317 µg g-1 in Lepista nuda, whereas the lowest Fe concentration was 211.7 µg g-1 in Calvatia utriformis. The highest Mn content was 36.55 µg g-1 for Russula delica, whereas the lowest Mn level was 24.5 µg g-1 for the species Bovista plumbea. The highest Ni content was found as 12.65 µg g-1 for Russula delica, whereas the lowest Ni level was 0.17 µg g-1 for Bovista plumbea. The highest Co content in the tested mushrooms was found as 3.5 µg g-1 for the species of Agaricus bisporus, whereas the lowest Co level was 0.85 µg g-1 for Polyporus frondosus. The results indicated that, in general, heavy metal contents in all mushroom species were lower than the underlying soil substrates except for some mushroom species. [ABSTRACT FROM AUTHOR]

A simple and sensitive method for the spectrophotometric determination of diosmin has been developed, and optimum reaction conditions along with other analytical parameters have been evaluated. Diosmin, as a phenolic compound, reacts with sodium nitroprusside and hydroxylamine hydrochloride in a basic medium to give a green-colored product. At analytical wavelength of 763 nm, Beer's law is obeyed over the concentration range 2-140 μg mL-1 of diosmin with a correlation coefficient of 0.9997. The molar absorptivity is 9671 L mol-1 cm-1. The limits of detection (LOD) and quantification (LOQ) are 0.05 and 0.2. μg mL-1, respectively. The method has been successfully applied to the determination of diosmin in a commercial pharmaceutical preparation. The results were compared favorably with those obtained by the 4-aminoantipyrine method. [ABSTRACT FROM AUTHOR]

Fire accelerants such as gasoline, kerosene, and diesel have commonly been used in arson cases. Improved analytical methods involving the extraction of fire accelerants are necessary to increase sample yield and to reduce the number of uncertain findings. In this study, an analytical method based on headspace single drop microextraction (HS-SDME) followed by gas chromatography-flame ionization detection (GC-FID) has been developed for the analysis of simulated fire debris samples. Curtain fabric was used as the sample matrix. The optimized conditions were 2.5 μL benzyl alcohol microdrop exposed for 20 min to the headspace of a 10 mL aqueous sample containing accelerants placed in 15-mL sample vial and stirred at 1500 rpm. The extraction method was compared with the solvent extraction method using n-hexane for the determination of fire accelerants. The HS-SDME process is driven by the concentration difference of analytes between the aqueous phases containing the analyte and the organic phase constituting the microdrop of a solvent. The limit of detection of HS-SDME for kerosene was 1.5 μL. Overall, the HS-SDME coupled with GC-FID proved to be rapid, simple and sensitive and a good alternative method for the analysis of accelerants in fire debris samples. [ABSTRACT FROM AUTHOR]

A novel poly (vinyl chloride) (PVC) membrane electrode sensitive to benzoate ions was developed. In this electrode, N,N'-bis(salicylidene)-1,2-diaminoethane zinc(II) (Zn(SDE)) complex served as the neutral carrier and o-nitrophenylocthyl ether (o-NPOE) as the plasticizer. We investigated the influences of the neutral carrier, the plasticizer and the composition of the PVC membrane on the potential responses of the electrode. The best response performance was achieved with the following composition (w/w) of the membrane: Zn(SDE): PVC: o-NPOE = 2.7: 32.6: 64.7. The electrode showed a sub-Nernstian response with a slope of -51.9 mV decade-1 in the concentrations range from 2.7 × 10-4 M to 1.0 × 10-1 M at pH 4.4. The electrode showed a better selectivity for benzoate ions than other anions such as [image omitted], [image omitted] and Cl-. The obtained mean recovery and standard deviation were 99.5% and 2.4% (n = 4), respectively. The content of sodium benzoate was successfully measured in a Zhacai sample, and benzoyl peroxide could also be analyzed through the hydrolysis-potentiometric method in a benzoyl peroxide sample. [ABSTRACT FROM AUTHOR]

Analytical results represent a very important part in a quality control program. Uncertainty estimation is an important step in method validation. The objective of this paper is to study the uncertainty of measurement estimation in the quantitative determination of codeine phosphate from pharmaceutical formulations using UV-VIS spectrophotometry. The uncertainty estimation was performed using the Ishikawa diagram. The estimation of uncertainty components proved to be a good way for the experimental model to obtain low contribution of uncertainty to the analytical result. [ABSTRACT FROM AUTHOR]

An obituary for George-Emil Baiulescu, Professor of Analytical Chemistry at the Faculty of Chemistry, University of Bucharest, Romania, is presented.

An immunosensors/sequential injection analysis system is proposed for the assay of thyroid hormones free L-T4 and free L-T3 in blood samples. The working concentration ranges for free L-T4 and free L-T3, are between 2.0 and 720.0 pmol/L and between 2.0 and 340.0 pmol/L, respectively, with detection limits of 1.0 and 1.7 pmol/L, respectively. The selectivity of the immunosensors, as well as the recovery tests done for free L-T4 and free L-T3 (99.90 ± 0.01% (n = 10) and 99.94 ± 0.02% (n = 10)), made the immunosensors/sequential injection analysis system suitable for the direct assay of thyroid hormones in blood samples. [ABSTRACT FROM AUTHOR]

A rapid and sensitive reversed phase high performance liquid chromatographic (HPLC) method was developed and validated for the analysis of tenoxicam in raw material and its pharmaceutical formulation. The analysis was carried out on a reversed phase C18 column, using mixtures of buffer/acetonitrile (40:60, v/v) with flow rate was of 1 mL min-1. The method was validated statistically for its linearity (correlation coefficient = 0.9983), accuracy, robustness, and intermediate precision. An experimental design was used during validation to evaluate method robustness and for the determination of intermediate precision. To test robustness, four factors were considered, mainly, percentage of organic modifier in the mobile phase, pH, flow rate, and different wavelengths. An increase of the flow rate results in a decrease of the drug concentration found, while the percentage of organic modifier, pH, and wavelength have no significant effect on the response. For intermediate precision the factors examined were multiple analysts, multiple instruments, and multiple days. The RSD value (0.49%, n = 24) indicated a good precision of the analytical method. Due to its simplicity, accuracy, sensitivity, and precision the method may be used for routine quality control analysis. [ABSTRACT FROM AUTHOR]

Today, chromatography is the back bone of separation science and is being used in all research laboratories and industries of the world. It has developed into nano liquid chromatography (NLC) modality through various kinds of chromatography. The present article describes a journey from Mikhail Tswett in 1903 to today of NLC. Attempts have been made to discuss the applications of newly developed NLC, especially for proteomic and genomic researches. Few chromatograms of NLC have been given for ready reference. The chromatographic journey is shown in the form of a chromatography tree. NLC is eco-friendly and may be referred to as green or clean chromatography. The future perspectives of chromatography have been highlighted. [ABSTRACT FROM AUTHOR]

A method based on hollow fibre liquid phase microextraction (HF-LPME) coupled with gas chromatography electron capture detection (GC-ECD) has been developed for the determination of organophosphorus pesticides (OPPs) (chlorpyrifos and profenofos) in vegetable samples. In this method, a microsyringe needle with 1.5 cm polypropylene hollow fibre containing a volume of organic acceptor phase (n-dodecane) was immersed in an aqueous donor solution, and at the completion of extraction, the acceptor phase was withdrawn and transferred to GC-ECD for analysis. The effects of extraction solvent, volume of acceptor phase, and volume of donor phase were investigated. The optimized conditions for HF-LPME of the selected OPPs were n-dodecane as organic solvent, 11 mL of donor phase, and 3 μL of acceptor phase. The correlation coefficient (r2) of the calibration curves ranged from 0.998 to 0.999. The limits of detection (LOD) were between 0.099 and 0.128 μg/mL. The developed method provided excellent RSDs ranging from 0.54% to 8.00% and analyte recoveries ranging from 60.8% to 88.0%. This method was applied successfully for determination of organophosphorus pesticides in selected vegetables. [ABSTRACT FROM AUTHOR]

A simple, rapid, and validated method for separation and determination of epinastine hydrochloride was developed. Epinastine hydrochloride enantiomers was separated and determined on a Chiralcel® OD-R column (250 × 4.6 mm i.d., 0.5 μm particle size), using a mixture of n-hexane: isopropanol: diethylamine: triflouroacetic acid (85: 15: 0.1: 0.1% v/v/v/v) as a mobile phase at 20°C and at a flow rate of 1 mL/min. The UV detector was set to 254 nm. Epinastine hydrochloride 1000 μg/mL was used as an external standard. The applied HPLC method allowed the separation and quantification of epinastine hydrochloride enantiomers with good linearity (r > 0.999) in the studied range. The relative standard deviations (RSD) were 1.076 and 0.769% for the epinastine hydrochloride enantiomers with accuracy of 99.65 and 99.77 for the enantiomeric pair separated. The limit of detection and limit of quantification of epinastine hydrochloride enantiomers were found to be 20 and 60 μg/mL, respectively. The method was validated through the parameters of linearity, accuracy, precision, and robustness. The HPLC method was applied for the quantitative determination of epinastine hydrochloride in pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

An isocratic, reversed phase liquid chromatographic (RPLC) method was developed for the quantitative determination of rivastigmine hydrogen tartrate, in bulk drugs and in pharmaceutical formulation. The chromatographic separation was achieved on A Vertex Hypersil reversed phase C18 column (25 cm × 4.6 mm i.d., particle size 5 μm) using acetonitrile and phosphate buffer. The procedure was validated by linearity (correlation coefficient = 0.9983), accuracy, robustness, and intermediate precision. An experimental design was used during validation to calculate method robustness and intermediate precision. For the robustness test, three factors were considered: percentage v/v of acetonitrile, flow rate, and temperature; an increase in flow rate results in decrease of the concentration of the drug from the expected value, while the percentage of organic modifier and temperature have no effect on the response. For intermediate precision measurement, the considered variables were analyst, equipment, and days. The RSD value (1.10%, n = 24) indicate a good precision. [ABSTRACT FROM AUTHOR]

A simple, sensitive, and cost effective capillary zone electrophoresis (CZE) method for the determination of the novel wake promoting agent, modafinil in pharmaceutical formulations has been developed and validated. The CZE separation was performed using 50 μm i.d × 56 cm fused silica capillary under the following conditions: capillary temperature, 25°C; applied voltage, 25 kV; 20 mM H3PO4 - 1 M tris running buffer (pH 9.0); detection wavelength, 225 nm. Phenobarbital was used as the internal standard. The method was validated and showed not only good precision and accuracy but also good robustness. The calibration was linear from 5 to 250 µg mL-1. The accuracy values ranged from 101.6 to 105.3%. The good accuracy values obtained indicate the potential of this method for the determination of the analyte in pharmaceutical formulations. The LOD and LOQ were 1.2 and 3.5 μg mL-1, respectively. The method has been successfully applied to the determination modafinil in pharmaceutical tablet formulations. Excipients present in the tablets and degraded products from different stress conditions did not interfere in the assay. [ABSTRACT FROM AUTHOR]

The research has been focusing on some connection between the chemical composition of the papers obtained by Fourier transform infrared (FTIR) spectroscopy and the nature of the fillers, determined by energy dispersion X-ray fluorescence (EDXRF) spectroscopy. The present paper corroborates the FTIR and EDXRF results obtained for some historical papers from books of the XIX-th and XX-th centuries, from private collections. These analytical results allowed a first approximation of technological paper composition and of the age determination of the samples. This analytical method can elaborate some properly methods for paper documents preservation, taking into account the aging and degradation processes of the historical paper. [ABSTRACT FROM AUTHOR]

It is known that the separation of several organic phosphonate esters using a tris(3,5-dimethylphenyl carbamate) cellulose (Chiralcel OD) column are better than the separation obtained using the Pirkle type chiral stationary phase (CSP), namely the N-(3,5-dinitrobenzoyl) leucine column. However, the elution order of the organic phosphonate esters enantiomers separated on tris(3,5-dimethylphenyl carbamate) cellulose chiral stationary phase is not known. The tandem use of these two CSPs together showed that the R-enantiomer had shorter retention time than S-enantiomer when tris(3,5-dimethylphenyl carbamate) cellulose chiral stationary phase was used. [ABSTRACT FROM AUTHOR]

A simple, rapid, and reliable potentiometric method is described for determination of ranitidine hydrochloride in pharmaceutical formulations. Experiments were performed to determine the suitability of using a chloride-ion selective electrode for the indirect estimation of ranitidine hydrochloride. The precision and accuracy of the potentiometric method were determined. We found that they not differ significantly. The advantage of the proposed method is the fact that it can be applied without filtration of the drug sample before analysis. [ABSTRACT FROM AUTHOR]

A stability-indicating reversed phase high performance liquid chromatographic assay procedure has been developed and validated for etodolac. The liquid chromatographic separation was achieved isocratically on C18 Zorbax ODS using a mobile phase containing methanol: water: acetic acid (70:30:0.1%, v/v/v), at a flow rate 1 mL/min and UV detection at 254 nm. The method was linear over the concentration range of 2.4-16 µg/mL (r = 0.9999) with a limit of detection and quantitation of 0.03 and 0.10 µg/mL, respectively. Another method was applied for the determination of etodolac in the presence of its degraded products using the first derivative ratio spectrophotometry (DD1) at 293 nm using 1000 µg of degraded etodolac as a divisor. The method was linear over the concentration range of 10-50 µg/mL (r = 0.9999). Both methods have been found to have the required accuracy, selectivity, sensitivity, and precision to assay etodolac in bulk form and in pharmaceutical dosage form. Degradation products resulting from the stress studies did not interfere with the detection of etodolac, which indicates that the assays are stability-indicating assays. [ABSTRACT FROM AUTHOR]

A differential pulse (DP) and square wave (SW) voltammetric techniques were developed for the determination of irbesartan. The electrochemical behavior of irbesartan was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV) at the hanging mercury drop electrode (HMDE). Different parameters were tested to optimize the conditions of the determination. It was found that in the range of 8 × 10-6-1 × 10-4 M, the currents measured by both of methods presented a good linear property as a function of the concentration of irbesartan. In addition, validation parameters, such as reproducibility, sensitivity, and recovery were evaluated as well. The slope of the log Ip- log ν linear plot was 0.58 indicating the diffusion control for 0.5 M sulphuric acid without the need for separation or complex sample preparation, since there was no interference from the excipients and endogenous substances. The methods were successfully applied to the analysis of irbesartan in the pharmaceutical tablet formulations and in human serum samples. [ABSTRACT FROM AUTHOR]

This paper describes the application of the common and variation peak ratio dual-index sequence analysis methods to evaluate the quality of several tea samples obtained from different species and different areas based on 1HNMR fingerprint spectra (FPS). The method is able to determine the most similar sample groups and identify accurately the varieties and qualities of Blank tea, Longjing tea, and other green tea samples. Longjing tea is a famous brand of local green tea and has its own distinct characteristics. There were obvious differences between Uji tea from Japanese and Chinese green tea. The results showed that the dual index sequent analytical method provides a good approach to accurately describe the resemblance and differences among tea samples. It also can reflect tea's integrity and individual difference, and is an effective method to evaluate the quality of tea samples. [ABSTRACT FROM AUTHOR]

Thousands of organic compounds are present in our water resources and exist in dynamic equilibrium with sediment. Among them are drug and pharmaceutical residues. Many of these residues are chiral, and their metabolites or degradation products may also be chiral in nature. Therefore, the determination of chiral ratio of these chiral compounds is required to predict the exact toxicities. The present article describes the presence of ibuprofen, the third most popular clinically used drug in the world, in water resources, its enantiomeric degradation, and the monitoring of chiral ratio of ibuprofen enantiomers and its degradation products. Attempts have also been made to describe the future scope of chiral analyses of drug and pharmaceutical residues in the environment. [ABSTRACT FROM AUTHOR]

Chloramphenicol (CAP) is the drug of choice for the treatment of typhoid fever and other diseases and is consumed by millions of people. Chloramphenicol is a broad-spectrum antibiotic, but it has serious side effects and high risk of anemia if taken continuously. The drug persists for a long time in the human body and is likely to damage to the liver, kidneys, and red blood cells, even at low concentrations. From the human health point of view, analysis of low levels of this drug in biological samples is important. This article present an overview of the analysis of CAP in biological samples by high-performance liquid chromatography (HPLC). In addition, the available methods are compared in terms of their applications, efficiencies, and effectiveness. [ABSTRACT FROM AUTHOR]

Fourier transform-infrared (FT-IR) spectrometry was used for the rapid, direct measurement of ascorbic acid (vitamin C) and biotin (vitamin H) in different pharmaceutical products. Conventional KBr spectra were compared for the best determination of active substances in drug preparations. The Beer-Lambert law and chemometric approaches were applied in data processing. [ABSTRACT FROM AUTHOR]

Simultaneous seasonal variation of four analogous taxanes, namely taxol (paclitaxel), cephalomannine, 10-deacetyl baccatin III (10-DAB), and baccatin III, from the needle of Iranian yew (Taxus baccata L.) has been monitored. Powdered samples of needles have been subjected to microwave-assisted extraction (MAE) and the extracted sample has been purified by liquid-liquid extraction (LLE) and analysis by reverse phase high performance liquid chromatography (RP-HPLC). These samples were identified by the LC-MS/MS system. The results indicated that taxane concentrations depend on seasonal and location. Analyses of these samples showed that 10-DAB has higher concentration than other taxanes and its highest concentration has been obtained in August. Thus, a heart cutting two-dimensional liquid chromatography was used for obtaining better resolution of taxanes. The first column in the analytical scale chromatography was a Eurospher-100 C8 and the second was Nucleosil-100 C18 which has been eluted at a flow rate of 1 mL min-1 with 70:30 v/v and 50:50 v/v water/acetonitrile, respectively. Optimized conditions in analytical chromatography have been extended to semipreparative scale in which the first column was a Eurospher-100 C8 and the second was a Eurospher-100 C18, both eluted with 70:30 v/v water/acetonitrile at a flow rate of 10 mL min-1. Detection has been carried out at a wavelength of 227 nm throughout the analysis in both scales. Final purity of the fraction containing 10-DAB, collected from the semipreparative column, is 82% after the first semipreparative run. Results have been confirmed by spiking of the standard 10-DAB sample and analysis by nuclear magnetic resonance (NMR). [ABSTRACT FROM AUTHOR]

Three enantioselective, potentiometric electrodes were proposed for the enantioanalysis of butaclamol. The electrodes were based on immobilization of maltodextrins (MDs) of different dextrose equivalences [4.0-7.0, I; 13-17, II; 16.5-19.5, III] into carbon paste. The electrodes based on MD I and II were used for the enantioanalysis of S-butaclamol within linear concentration ranges of 10-10 to 10-7 and 10-10 to 10-8, respectively, with slopes of 51.20 and 57.59 mV/decade of concentration; whereas the electrode based on MD III was used for the enantioanalysis of R-butaclamol within a linear concentration range between 10-10 and 10-7 with a slope of 58.50 mV/decade of concentration. Recoveries greater than 90% were recorded for the enantioanalysis of butaclamol in synthetic and urine samples. [ABSTRACT FROM AUTHOR]

Chiral resolution has achieved an independent identity in the separation sciences and polysaccharide CSPs are viewed as effective and efficient CSPs due to their many unique advantages. The present review article highlights the separations of chiral pharmaceuticals and drugs by liquid chromatographic modalities (high performance liquid chromatography, capillary electro-chromatography, sub- and super critical fluid chromatography and thin layer chromatography) utilizing polysaccharide CSPs. Enantiomeric resolution at analytical and preparative scales and a comparison of coated and immobilized CSPs is discussed. The optimization strategies for enantiomeric separation have also been presented. The possible mechanisms of chiral resolution of racemates were also included. The commercial CSPs of all the Companies i.e., Daicel, Kromasil, Macherey Nagel, Knauer and Sepaserve have been compared and discussed. Finally, the role of these CSPs in chiral drugs development programs has also been identified. [ABSTRACT FROM AUTHOR]

Maltodextrins with different dextrose equivalent (DE) values (maltodextrin I: DE 4.0-7.0; maltodextrin II: DE 13.0-17.0; maltodextrin III: DE 16.5-19.5) were used for the design of three enantioselective, potentiometric membrane electrodes (EPMEs) for the assay of S-ketoprofen. The linear concentration ranges for the proposed electrodes were 10-10 to 10-8, 10-9 to 10-5, and 10-10 to 10-7 mol/L, with slopes of 58.0, 58.67, and 58.93 mV/decades of concentration and limits of detection of 1.49 × 10-8, 2.43 × 10-8, and 4.19 × 10-11 mol/L for EPMEs based on maltodextrin I, II, and III, respectively. The EPMEs showed high reliability and effectiveness for the enantioanalysis of S-ketoprofen raw material and its pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

The internal solid contact potentiometric sensors (ISCSs) based on the use of conducting polymers (e.g. polypyrrole (PPy), polyaniline(PAn) etc.) as inner contact ion-to-electron transducer material and ion-selective polymeric membrane as the ion sensing membrane possess pronounced potential stabilities, in comparison with the coated wire electrodes. Furthermore, the response performances of ISCS are mainly dependent on the composition of the polymeric sensing membrane including the types of ionophore, plasticizer, ionic additives, and their mass percentages. This study is focused on investigating experimentally whether there is a negligible effect of an anion doped within PPy film for an ISCS on the response performances of the sensor or not. Five anions including Cl-, [image omitted], SCN-, ClCH2COO- and Cl3CCOO- were used as the doped anions and five types of ion exchanger were used as the electroactive substances in the ion-selective PVC membranes to fabricate these sensors. The results indicate that the nature of dopant can influence the response behaviors, such as detection limit, response slope and potential selectivity, of the ISCSs to some extent, which are dependent on the type of primary ion tested. The size and lipophilicity of dopant in PPy layer could be important factors influencing response performances of an ISCS. The origin of the influences has been discussed from models proposed in this paper. [ABSTRACT FROM AUTHOR]

An enantioselective, potentiometric membrane electrode based on 2-hydroxy-3-trimethylammoniopropyl-β-cyclodextrin (as its chloride salt) physically immobilized in carbon paste was proposed for the enantioanalysis of R-Clenbuterol. The linear concentration range was between 10-6 and 10-3 mol/Lwith a detection limit of 2.99×10-7 mol/L. R-Clenbuterol was recovered from synthetic as well as from serum samples with average recoveries higher than 99.10%. [ABSTRACT FROM AUTHOR]

Differentiating between black powder toners used in laser printers and copiers can be challenging for forensic examiners. One hundred and eight samples from different types of cartridges produced by 10 manufacturers were studied using reflection-absorption infrared microscopy (R-A IR). The grouping of copy toners into distinguishable classes, achieved by visual comparison and computer-assisted spectral matching, was compared to that achieved by multivariate discriminant analysis. The FTIR spectra were classified into 15 groups. This classification served as a basis for the development of an analytical scheme for differentiating black powder toners. Obtained spectra and all the available information could be used to create a database. The results obtained confirm the multiplicity and compatibility of toners. [ABSTRACT FROM AUTHOR]

A study was undertaken to examine the possibility of qualitative analysis of photocopy and laser printers toners by three different microscopic infrared spectrometry techniques: Diffuse Reflectance (DRIFTS), microscopic Attenuated Total Reflectance (μATR), and microscopic Reflection-Absorption (μRA), respectively, with a variety of reflecting media including mirrored slides, low emissive glass, or aluminum foil. Selection of the analysis technique can be made based on equipment availability, ease of sample preparation, speed of analysis, and importance of the original document to determine if a mildly destructive technique can be used. [ABSTRACT FROM AUTHOR]

Raman spectroscopy has recently become more popular for the chemical analysis of several types of materials of forensic interest. The Raman technique allows the measurement of the inelastic scattering of light due to the vibrational modes of a molecule when irradiated by an intense monochromatic source such as a laser. Forensic laboratories must often work with small samples in order to determine the type of material and its possible manufacturer for investigatory and evidence purposes. This paper describes the analysis of a color photocopied document for the identification of the particular type of toner used in the generation of the document. [ABSTRACT FROM AUTHOR]

This article describes the development and validation of a quantitative analytical method for determination of estradiol in several pharmaceutical products (powder, tablets, cream, solutions for injection) using UV-vis molecular absorption spectrometry. The proposed method is accurate, precise, sensitive, and selective and can be used in quality control laboratories. [ABSTRACT FROM AUTHOR]

A precise and accurate flow injection analysis method for the quantification of ticlopidine in pharmaceuticals is described. An aqueous carrier stream, which was entirely prepared with water was chosen for the flow injection analysis. The method development was achieved by using a reference standard solution of ticlopidine at 3.19 × 10-6 M concentration, which was prepared in water. The solution was injected into the instrumental system at a flow rate of 1.0 mL·min-1 and signals were detected by a UV detector at 214.2 nm. The calibration curves of TP were linear in the concentration range of 1.59 × 10-6 - 7.99 × 10-5 M. The intra- and inter-assay precision was less than 1.3% relative standard deviation. The method exhibited good linearity with the correlation coefficients close to unity. The limit of detection and limit of quantization concentrations were found to be 8.91 × 10-8 and 2.70 × 10-7 M, respectively. The effects of the tablet excipients were insignificant at the 95% probability level. The calculated tablet contents were around 99%, which is in agreement with the ranges stated by pharmacopoeias. [ABSTRACT FROM AUTHOR]

The relative-area difference sequence (ΔSr sequence) analytical method is proposed, with which the most similar herbal samples can be determined according to their contents. Together with common and variation peak ratio dual-index sequence analysis, one can identify the most similar sample group in the two-dimensional sequence accurately; therefore, the method can evaluate the quality of herbs. [ABSTRACT FROM AUTHOR]

A simple, rapid, and validated method for separation and determination of terbutaline enantiomers was developed. Terbutaline was separated and determined on a Vancomycin Chirobiotic V column (250 × 4.6 mm), using a mixture of methanol, acetic acid, and triethylamine (100:0.1:0.1% v/v/v) as a mobile phase at 20°C and at a flow rate of 1 ml/min. The UV detector was set to 276 nm. Acetyl salicylic acid (aspirin) was used as an internal standard. The applied high-performance liquid chromatography (HPLC) method allowed separation and quantification of terbutaline enantiomers with good linearity (r > 0.999) in the studied range. The relative standard deviations (RSD) were 1.10 and 1.32% for the terbutaline enantiomers with accuracy of 99.80 and 99.55. The limit of detection and limit of quantification of terbutaline enantiomers were found to be 0.05 and 0.10 µg · ml-1, respectively. The method was validated through the parameters of linearity, accuracy, precision, and robustness. The HPLC method was applied for the quantitative determination of terbutaline in pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

Chloramphenicol is a classical antibiotic, used for the treatment of typhoid fever all over the world. Some potential manufacturers and users dealing with chloramphenicol are contaminating our natural water resources by discharging their effluents. Therefore, a sensitive, inexpensive, fast, and reproducible HPLC-SPE method was developed for the analysis of chloramphenicol in the wastewater. The column used was monolithic, chromolith performance RP-18e, 100-4.6 (100 × 4.6 mm). The mobile phase used was phosphate buffer (100 mM, pH 3.0)-acetonitrile (75:25, v/v) at 1.5 mL/min with UV detection at 275 nm. The retention, separation, and resolution factors of chloramphenicol were 3.13, 2.0, and 4.30, respectively. The percentage recovery of chloramphenicol from wastewater was 94.0%. Frusemide was used as the internal standard to access the percentage extraction of chloramphenicol from wastewater. [ABSTRACT FROM AUTHOR]

Five polysaccharide based chiral stationary phases have been used for separation of enantiomers of fourteen heterocyclic oxiranes. The polysaccharide based chiral stationary phases used in this study are Chiralak AD, Chiralpak AS, Chiralcel OD, Chiralcel OG, and Chiralcel OJ. From the chiral separation results, the chiral separation ability for the selected compounds show the order of Chiralpak AD > Chiralcel OD > Chiralcel OJ > Chiralcel OG > Chiralpak AS. Chiralcel OD appears to be quite versatile, since 8 out of 11 oxiranes with π-aromatic system were successfully resolved, yet no resolution was obtained for those oxirane derivatives, which lacks the π-aromatic system. Although Chiralcel OD is also versatile, it was not as effective; since the separation factors (α) are much smaller. The results indicate that dipole interactions have a strong impact on the retention mechanism, and extended π systems are essential. The spatial arrangement of the substituent groups around the analyte stereogenic center plays an important role in enantiomeric separations. The closer a group is to the chiral center, the more likely is the chiral recognition and enantioselectivity. [ABSTRACT FROM AUTHOR]