Methanolic HCl Research Articles

Finger millet (Eleusine coracana) polyphenols: Investigation of their antioxidant capacity and antimicrobial activity

Finger millet (Eleusine coracana) or ragi, one of the important minor cereals is a rich source of several phytochemicals and among them polyphenols are the most important because of their nutraceutical potentials. The seed coat-rich fraction (SCF) of the millet contains over 70% of polyphenols of the millet. Treated with different polar and non-polar solvents as such and after acidification with HCl for the extraction, it was observed that the polar solvents extracted more (1.7 to 7.4%) than the non-polar solvents (0.28 to 1.54%) while the 1% HCl–methanol extracted the highest proportion of polyphenols (13%). Fractionation of extracted polyphenols by HPLC revealed the presence of a large number of constituent phenolics. The inhibitory concentration (IC50) values for the antioxidant activity of the polyphenols determined in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and 2, 2’- azinobis – 3 – ethylbenzothiazoline – 6 – sulfonate (ABTS) radicals scavenging activities of acidified methanolic extract, were 63, 109, and 114 µg/mL phenolic, respectively. The polyphenols extracted from finger millet seed coat using 1% HCl –methanol was fractionated by reverse phase– high performance liquid chromatography (RP-HPLC) and the constituent phenolics were characterized by electrospray ionization mass spectrometry (ESI-MS) and NMR. The phenolics identified were the benzoic acid derivatives (gallic, protocatechuic, p-hydroxybenzoic, vanillic, and ferulic acids) and cinnamic acid derivatives (syringic, trans-cinnamic and p-coumaric acids); and also a flavonoid compound namely, quercetin. The millet polyphenols showed proliferation inhibitory activities on Escherichia coli, Bacillus cereus, Staphylococcus aureus,Listeria monocytogenes, Streptococcus pyogenes, Proteus mirabilis, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella pneumonia, and Yersinia enterocolitica. Quercetin exhibited substantial inhibition of the growth of these pathogenic bacteria revealing the potential nutraceutical properties of the millet polyphenols. From the observation, it could be inferred that finger millet polyphenols could be used as natural source of antioxidants especially for minimizing the risk of diseases arising from oxidative deterioration. Key words: Finger millet, polyphenols, antioxidant activity, 1, 1-diphenyl-2-picrylhydrazyl (DPPH), radical scavenging activity.

Combined quantification of faecal sterols, stanols, stanones and bile acids in soils and terrestrial sediments by gas chromatography–mass spectrometry

Faeces incorporation can alter the concentration patterns of stanols, stanones, Δ5-sterols and bile acids in soils and terrestrial sediments. A joint quantification of these substances would give robust and specific information about the faecal input. Therefore, a method was developed for their purification and determination via gas chromatography–mass spectrometry (GC–MS) based on a total lipid extract (TLE) of soils and terrestrial sediments. Stanols, stanones, Δ5-steroles and bile acids were extracted by a single Soxhlet extraction yielding a TLE. The TLE was saponified with KOH in methanol. Sequential liquid–liquid extraction was applied to recover the biomarkers from the saponified extract and to separate the bile acids from the neutral stanoles, stanones and Δ5-steroles. The neutral fraction was directly purified using solid phase extraction (SPE) columns packed with 5% deactivated silica gel. The bile acids were methylated in dry HCl in methanol and purified on SPE columns packed with activated silica gel. A mixture of hexamethyldisilazane (HMDS), trimethylchlorosilane (TMCS) and pyridine was used to silylate the hydroxyl groups of the stanols and Δ5-sterols avoiding a silylation of the keto groups of the stanones in their enol-form. Silylation of the bile acids was carried out with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) containing N-trimethylsilylimidazole (TSIM). TLEs from a set of soils with different physico-chemical properties were used for method evaluation and for comparison of amounts of faecal biomarkers analysed with saponification and without saponification of the TLE. Therefore, a Regosol, a Podzol and a Ferralsol were sampled. To proof the applicability of the method for faecal biomarker analyses in archaeological soils and sediments, additional samples were taken from pre-Columbian Anthrosols in Amazonia and an Anthrosol from a site in central Europe settled since the Neolithic. The comparison of the amounts of steroids in combination with and without saponification of the TLE showed that high amounts of faecal biomarkers occur bound to other lipids and were liberated by saponification. The method was evaluated by standard addition. The standard contained 5β-stanols, 5β-stanones and their 5α-isomers together with Δ5-sterols and bile acids (19 substances). The standard addition revealed mean recoveries of individual substances ≥85%. The recoveries of biomarkers within each biomarker group did not differ significantly. Precisions were ≤0.22 (RSD) and quantification limits were between 1.3 and 10ngg−1 soil. These data showed that the method can be applied for quantification of trace amounts of faecal steroids and for the analyses of steroid patterns to detect enhanced faeces deposition in soils and sediments.

Chloride-free Cu-modified SAPO-37 catalyst for the oxidative carbonylation of methanol in the gas phase

The substitution of harmful phosgene or chloride-containing catalysts in the synthesis of dimethyl carbonate (DMC) and its use as “green solvent” or polycarbonate building block direct its manufacture towards environmental benign syntheses. Thus, copper was introduced into silicoaluminophosphate structure SAPO-37 (belonging to the same FAU structure family like aluminosilicate zeolites Y and X) by solid state ion exchange (SSIE) using Cu(II) acetyl acetonate. This strategy circumvented structural breakdown being observed when using aqueous copper solutions for impregnation or ion exchange. The SSIE efficiently ran when the organic template is widely extracted from the synthesis form of SAPO-37, e.g. through treatment with methanolic HCl. The parent SAPO-37, template-free SAPO-37 and Cu-SAPO-37 materials were characterized by XRD, TG, temperature programmed reduction (TPR), temperature programmed desorption of ammonia (TPDA) and FTIR spectroscopy of adsorbed pyridine and CO. The Cu-SAPO-37 catalyst pre-treated in inert gas exhibits a high selectivity for DMC and dimethoxymethane (DMM) in the oxidative carbonylation of methanol (OCM). The catalytic behavior of Cu-SAPO-37 is shown to be comparable with those of a Cu-containing Y zeolite catalyst that is so far regarded as one of the best chloride-free catalyst for the OCM reaction in the gas phase.

Development of a simultaneous analytical method for selected anorectics, methamphetamine, MDMA, and their metabolites in hair using LC-MS/MS to prove anorectics abuse

Owing to the tight control of methamphetamine, it is presumed that phentermine, an amphetamine-type anorectic, has recently been considered a supplement for methamphetamine abusers in Korea. In addition, the abuse of other anorectics obtained by inappropriate means has become a social issue. Hair is a useful specimen to prove chronic drug use. Therefore, an analytical method for the simultaneous detection of phentermine, phendimetrazine, amfepramone, fenfluramine, mazindol, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA), as well as their metabolites, which covers the major amphetamines and anorectic agents in Korea, in hair was established and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The drugs and their metabolites in hair were extracted using 1 % HCl in methanol and then filtered and analyzed by LC-MS/MS with electrospray ionization in positive mode. The validation results for selectivity, linearity, matrix effect, recovery, process efficiency, intra- and interassay precision and accuracy, and processed sample stability were satisfactory. The limits of detection ranged from 0.025 to 1 ng/10 mg hair and the limits of quantification were 0.25 ng/10 mg hair for every analyte except mazindol and phentermine, for which they were 10 ng/10 mg hair. The method was successfully applied for the segmental determination of selected anorectics, methamphetamine, MDMA, and their metabolites in hair from 39 drug suspects. Among the anorectics, phentermine and/or phendimetrazine were identified with or without methamphetamine in the hair samples. Closer supervision of the inappropriate use of anorectics is necessary. Also, hair analysis is useful for monitoring the abuse potential of unnoticed drugs.

ESTIMATION OF DEXTROMETHORPHAN HYDROBROMIDE AND QUINIDINE SULPHATE IN THEIR COMBINED DOSAGE FORMS USING SIMULTANEOUS EQUATION METHOD

A simple, accurate, precise and specific simultaneous equation method has been developed and validated for simultaneous estimation of dextromethorphan hydrobromide and quinidine sulphate in their combined dosage form approved by USFDA (brand name Nuedexta capsules) in October 2010. Absorbances were measured in 0.5 M methanolic HCl at 226 nm (?max of dextromethorphan) and at 253 nm (?max of quinidine). Beers law was followed within the range of 5-40 mcg/mcL for dextromethorphan with coefficient of correlation 0.9997 and 2-18 mcg/mcL and for quinidine with coefficient of correlation 0.998. LOD and LOQ for dextromethorphan was found to be 1.36 mcg/mL and 4.55 mcg/mL while for quinidine it was 0.34 mcg/mL and 1.14 mcg/mL. Results of accuracy, precision and specificity were well within acceptance criteria which indicate that the method has excellent scope for simultaneous estimation of dextromethorphan and quinidine in combined dosage form.

Effect of diets supplemented with Ethiopian pepper [Xylopia aethiopica (Dun.) A. Rich (Annonaceae)] and Ashanti pepper [Piper guineense Schumach. et Thonn (Piperaceae)] on some biochemical parameters in normal rats

ObjectiveTo investigate and compare the in vitro and in vivo antioxidant capacity of Ethiopian pepper [Xylopia aethiopica (Dun.) A. Rich (Annonaceae)] and seeds of Ashanti pepper [Piper guineense Schumach. et Thonn (Piperaceae)]. MethodsBoth spices were each extracted with methanol and 1M HCl (1:1, w/v) mixture to give the phenolic-rich extracts, which were used for the in vitro analyses [total phenol, total flavonoid and antioxidant properties (reducing properties, 1,1 diphenyl-2— picrylhydrazyl (DPPH) and 2,2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate (ABTS*) radical scavenging abilities]. Thereafter, thirty male albino rats were divided into five groups of six. Group I represented control group; Group II & III were fed diet containing 2% Ethiopian pepper & 4% XA while Group IV & V ate diet supplemented with 2% and 4% Ashanti pepper. ResultsThe results suggest that diet supplemented with 2% and 4% Ethiopian pepper and Ashanti pepper could enhance some in vivo antioxidant status, maintain membrane integrity and protect the liver against oxidative stress. ConclusionsThis could be attributed to the phenolic contents and the in vitro antioxidant properties of the Ethiopian pepper and Ashanti pepper. However, dietary supplementation with 4% Ethiopian pepper showed the most promising protective potentials.

Simultaneous determination of non‐steroidal anti‐inflammatory drugs in river water by gas chromatography‐mass spectrometry

The gas chromatography/mass spectrometric assay method was developed for the determination of 13 non-steroidal anti-inflammatory drugs (NSAIDs) in river water. Extraction was achieved by a liquid-phase extraction procedure using methylene chloride. The extract was reacted for 30 min at 80°C based on the formation of methyl ester with 1.0 M HCl in methanol and extraction of the derivative with ethyl acetate, which was then measured by gas chromatography-mass spectrometry. The limit of quantification of NSAIDs was 1.0-60 ng/L and the calibration curve showed linearity being greater than r=0.997. The method was used to analyze ten river water samples from various regions in Korea. Diclofenac, indoprofen, ketoprofen and loxoprofen were detected at concentration of up to 1.29 μg/L in river water. The developed method may prove valuable for use in the national monitoring project of NSAIDs in surface water.

Determination of sphingoid bases from hydrolyzed glucosylceramide in rice and wheat by online post-column high-performance liquid chromatography with O-phthalaldehyde derivatization

We developed a determination method for sphingoid bases using online post-column high-performance liquid chromatography (HPLC) with O-phthalaldehyde (OPA) derivatization. Good separation was achieved using a reversed-phase column and eluting with 50% acetonitrile containing formic acid and heptafluorobutyric acid. Using these conditions, an excellent linearity (R² > 0.999) was achieved using standard solutions of sphinganine (d18:0), sphingosine (d18:1(4t)), 4-hydroxy-sphinganine (t18:0), glucosylsphingosine (glc-d18:1(4t)), and galactosylsphingosine (gal-d18:1(4t)). Plant glucosylceramides were hydrolyzed with 1 M aqueous HCl in methanol for 18 h at 90°C, followed by extraction of sphingoid bases with diethyl ether in preparation for analysis using the proposed HPLC conditions. The glc-d18:1(4t) standard was also hydrolyzed and analyzed by HPLC using the same procedure, and the d18:1(4t) peak obtained from the hydrolyzed glc-d18:1(4t) standard was used as a reference for calculation. We also confirmed the applicability of this method to the analysis of sphingoid bases in rice and wheat, obtaining relative standard deviations of 8.0% for rice and 4.6% for wheat. The recoveries of spiked rice and wheat samples were 104% and 106%, respectively. Our proposed method enables the straightforward determination of sphingoid bases without expensive facilities, employing fluorescence detection of OPA derivatives.

Radical-mediated nitrile translocation as the key step in the stereoselective transformation of 2-(4-chloro-2-cyanobutyl)aziridines to methyl cis-(1-arylmethyl-4-phenylpiperidin-2-yl)acetates

Non-activated 2-(4-chloro-2-cyano-2-phenylbutyl)aziridines were used as building blocks for the stereoselective synthesis of novel cis-2-cyanomethyl-4-phenylpiperidines via a microwave-assisted aziridine to piperidine ring expansion followed by a radical-induced nitrile translocation through initial formation and subsequent cleavage of intermediate bicyclic iminyl radicals. Furthermore, these 2-(cyanomethyl)piperidines were shown to be eligible substrates for the preparation of methyl cis-(1-arylmethyl-4-piperidin-2-yl)acetates through a Pinner reaction using gaseous HCl in methanol.

Amino acid vinyl esters: a new monomer palette for degradable polycationic materials

Toward the goal of developing degradable polycationic materials with tunable backbone charge densities and hydrophilicities, we report the optimized syntheses and polymerization activities of a series of N-Boc-protected amino acidO-vinyl ester (BAAVE) monomers derived from Boc-protected glycine, alanine, valine, and proline. The homopolymerization and copolymerization behaviors of these monomers under thermally initiated conventional free radical polymerization conditions are studied. By conducting copolymerizations of (N-tert-butoxycarbonyl)glycine vinyl ester (BGVE) with vinyl acetate (VAc) at various feed ratios and by analyzing the compositions of the resulting polymers produced at 88 °C using 1,1′-azobis(cyclohexane-1-carbonitrile) (V-40) initiation, we find that the reactivity ratios are rBGVE = 1.61 ± 0.12 and rVAc = 0.82 ± 0.07. Treatment of poly(VAc-co-BAAVE) with neat CF3COOH selectively unmasks the Boc-protected amine functionalities to furnish cationic poly(VAc-co-AAVE·CF3COOH) copolymers. Alternatively, treatment of these random copolymers with methanolic HCl results in the complete hydrolysis of both the Boc-protecting groups as well as the acetate esters, enabling access to well-defined, hydrophilic, polycationic amino acid ester-functionalized poly(vinyl alcohol) materials.

Comparative studies of acidic and enzymatic hydrolysis for production of soyasapogenols from soybean saponin

Soyasapogenols, aglycones of soyasaponins, can be produced from crude soybean saponin extract by acid or enzymatic hydrolysis. Soyasapogenol B is known to have hepatoprotective, antimutagenic, antivirus, and anti-inflammatory activities. Hydrolysis of soyabean saponin extract for 72 h with 2 M HCl in methanol gave three soyasapogenols, namely: soyasapogenol D, soyasapogenol B1 and soyasapogenol A. However, the microbial hydrolysis of soybean saponin extract by Aspergillus terreus led to isolation of soyasapogenol B as a major product. A systematic evaluation of the effect of key operational parameters on the microbial transformation was performed. Maximum production of soyasapogenol B (about 152.3 mg/50ml) was observed using 1.5% (w/v) soybean saponin and 1.5% (w/v) glucose, 32°C after 72 h at pH 7 using phosphate buffer. Under these optimal conditions, the cells’ bioconversion efficiency increased from 20.5 to 85.3%. The isolation of soyasapogenols was performed using chromatographic methods and their structures identified on the basis of spectroscopic tools.

Synthesis of some new 1H‐benzimidazole‐2‐carboxamido derivatives and their antimicrobial activitiy

Abstract5,6‐Dichloro‐2‐hydroxymethyl‐1H‐benzimidazole (1) was prepared by the cyclization of 4,5‐dichloro‐o‐phenylenediamine with glycolic acid, then, alcohol group of 1 was converted to carboxylic acid (2). The final products 5,6‐dichloro‐1H‐benzimidazole‐2‐carboxamides (3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14) were prepared by the amidification of compounds 2 with several amines by using O‐(benzotriazol‐1‐yl)‐N,N,N′,N′‐tetramethyluronium hexafluorophosphate. Compound 12 was prepared by the reaction of compound 6 with methanolic HCl. The relations between the tautomer and nontautomer types of imidazole moiety are discussed with NMR spectroscopy. The in vitro antibacterial and antifungal activity of the synthesized compounds against S. aureus, E. coli, B. subtilis, and C. albicans were evaluated with the disc diffusion techniques. The synthesized compounds were more active against the bacteria than fungi. Compound 3 exhibited best inhibitory activity against S. aureus. J. Heterocyclic Chem., (2011).

Quantification of sterol lipids in plants by quadrupole time-of-flight mass spectrometry

Glycerolipids, sphingolipids, and sterol lipids constitute the major lipid classes in plants. Sterol lipids are composed of free and conjugated sterols, i.e., sterol esters, sterol glycosides, and acylated sterol glycosides. Sterol lipids play crucial roles during adaption to abiotic stresses and plant-pathogen interactions. Presently, no comprehensive method for sterol lipid quantification in plants is available. We used nanospray ionization quadrupole-time-of-flight mass spectrometry (Q-TOF MS) to resolve and identify the molecular species of all four sterol lipid classes from Arabidopsis thaliana. Free sterols were derivatized with chlorobetainyl chloride. Sterol esters, sterol glycosides, and acylated sterol glycosides were ionized as ammonium adducts. Quantification of molecular species was achieved in the positive mode after fragmentation in the presence of internal standards. The amounts of sterol lipids quantified by Q-TOF MS/MS were validated by comparison with results obtained with TLC/GC. Quantification of sterol lipids from leaves and roots of phosphate-deprived A. thaliana plants revealed changes in the amounts and molecular species composition. The Q-TOF method is far more sensitive than GC or HPLC. Therefore, Q-TOF MS/MS provides a comprehensive strategy for sterol lipid quantification that can be adapted to other tandem mass spectrometers.

Simultaneous determination of serine enantiomers in plasma using Mosher's reagent and stable isotope dilution gas chromatography‐mass spectrometry

D-Serine is a co-agonist of the N-methyl-D-aspartate receptor in glutamate neurotransmission and has been proposed as a potential therapeutic agent for schizophrenia. However, D-serine also acts as a nephrotoxic substance in rats at high doses. To investigate the pharmacokinetics and toxicokinetics of D-serine, a method for the stereoselective determination of serine enantiomers in rat plasma was developed using GC-MS with selected ion monitoring (GC-MS-SIM). DL-[(2)H(3)]Serine was used as an internal standard to account for losses associated with the extraction, derivatization and chromatography. Serine enantiomers were purified by cation-exchange chromatography using BondElut SCX cartridge and derivatized with HCl in methanol to form methyl ester followed by subsequent N,O-diacylation with optically active (+)-α-methoxy-α-trifluoromethylphenylacetyl chloride to form epimeric amide. Quantitation was performed by SIM of the molecular-related ions of the epimers in the chemical ionization mode. The intra- and inter-day reproducibility of the assay was less than 5% for D-serine and 3% for L-serine. The method was successively applied to study the pharmacokinetics of D-serine in rats.

Simultaneous determination of selenomethionine enantiomers in biological fluids by stable isotope dilution gas chromatography–mass spectrometry

A method for the stereoselective determination of d- and l-enantiomers of selenomethionine in mouse plasma was developed using gas chromatography–mass spectrometry with selected-ion monitoring (GC–MS-SIM). dl-[ 2H 3, 82Se]selenomethionine was used as analytical internal standard to account for losses associated with the extraction, derivatization and chromatography. Selenomethionine enantiomers in mouse plasma were purified by cation-exchange chromatography using BondElut SCX cartridge and derivatized with HCl in methanol to form methyl ester followed by subsequent N-acylation with optically active (+)-α-methoxy-α-trifluoromethylphenylacetyl chloride to form diastereomeric amide. Quantification was performed by SIM of the molecular-related ions of the diastereomers on the chemical ionization mode. The intra- and inter-day precision for d- and l-selenomethionine spiked to mouse plasma gave good reproducibility with relative standard deviation of 3% and 3% for d-selenomethionine and 6% and 3% for l-selenomethionine, respectively. The estimated amounts were in good agreement with the actual amounts spiked, the intra- and inter-day relative error being 5% and 2% for d-selenomethionine and 2% and 1% for l-selenomethionine, respectively. The present method is sensitive enough to determine pharmacokinetics of selenomethionine enantiomers.

Feasibility of rat hair as a quality control material for the determination of methamphetamine and amphetamine in human hair

A quality control material (QCM) is a necessity in hair drug analysis, but it is not always easy to have an authentic hair sample containing various target drugs and metabolites. In the present study, the feasibility of rat hair as a QCM was examined for its application in the determination of methamphetamine (MA) and amphetamine (AP) in human hair. MA was administered to lean Zucker rats, from which only pigmented hair was collected for the preparation of a QCM. The rat hair was then washed, homogenized and finally bottled. Both homogeneity and stability were examined in order to demonstrate the suitability of rat hair as a QCM in hair drug analysis. The concentrations of MA and AP in each bottle were determined using extraction with 1% HCl in methanol at 38°C followed by gas chromatography/mass spectrometry after derivatization with trifluoroacetic anhydride. Furthermore, the prepared QCM was used in an inter-laboratory quality assurance program. In the homogeneity test, no significant difference was observed between bottles of the QCM. The statistical results also showed no significant trends in stability for three months at room temperature. An inter-laboratory quality assurance program was also performed successfully using this material. Thus, rat hair will be useful as an alternative QCM sample for the determination of a variety of drugs and their metabolites in human hair.

Synthesis of 6,8-Diarylimino-7H-Pyrano[3,2-c:5,6-c’]Dicoumarins; Chemoselective Hydrolysis of the Ether- and Imino-Functions

POCl3-induced dehydration of 3,3'-methylenedi(2-arylamino-4 H-chromen-4-ones) gives 6,8-diarylimino-7 H-pyrano[3,2- c:5,6- c’]dicoumarins, which undergo chemoselective hydrolysis of the imino function to form 7 H-pyrano[3,2- c:5,6- c’]dicoumarins by heating with HCl in methanol However, cleavage of the ether function occurs upon heating in acetic acid to give 3,3'-methylenedi(2-arylamino-4 H-chromen-4-ones).

Effect of Sulfuric Acid on Corrosion and Passivation of 316 SS in Organic Solution

Organic solvents like methanol have potential application in fuel cells, chemical and surface treatment processes. The corrosion investigation of austenitic stainless steels in methanol containing reducing acids (HCl, H2SO4 etc.) is very limited, in particular the passivation and pitting kinetics. In this work, the corrosion, passivation and pitting kinetics of 316 stainless steel (SS) have been investigated in methanolic solutions containing LiCl, HCl and mixture of HCl and H2SO4 by polarization, EIS, SEM and XPS. The rate of corrosion was higher in HCl solutions as compared to LiCl solutions. Passivation was promoted in methanol–HCl + H2SO4 solutions with molar ratio of H2SO4 to HCl ≥ 10: 1. The presence of anions, water content and solution acidity were the key factors determining the stability of passive film. Pit nucleation was inhibited with increasing H2SO4 concentration. Primary components of the passive film were iron/chromium oxyhydroxides with incorporated and ions.

Spectrophotometric method for quantitative determination of triclabendazole in bulk and pharmaceutical

Background: Triclabendazole (TCBZ, 6-chloro-5(2-3 dichlorophenoxy)-2-methyl thio-benzimidazole), an halogenated benzimidazole (BZD) thiol derivative, shows high efficacy against both the immature and mature stages of Fasciola hepatica in sheep and cattle, which is a differential feature compared to other available trematodicidal drugs. As a consequence of its excellent activity against the liver fluke, it has been extensively used and this has inevitably promoted the selection of TCBZ-resistant populations, which is now a worrying problem in several areas of the world. We propose simple ultraviolet spectrophotometric method for the estimation of triclabendazole in 0.1 methanolic HCl for the estimation of the drug. Method was validated as per ICH guidelines. Materials and Methods: Spectral absorbance measurements were made on Shimadzu UV-1800 with 10 mm matched quartz cells and dilutions were made in 0.1 M methanolic HCl. Results: The LOD and LOQ of triclabendazole at 305 nm were found to be 0.068434 and 2.73×10-4 μg/ml respectively. The calibration was linear in the range of 1-10 μg/ml. Analytical parameters such as stability, selectivity, accuracy, and precision have been established for the method in Endex and Fasinex tablets and evaluated statistically to assess the application of the method. Conclusion: Method passes all parameters with in desirable limits and found to be simple, stable, sensitive, reproducible, and accurate for the routine analysis of the drug in pharmaceutical formulations and in pharmaceutical investigations involving triclabendazole.

Application of dispersive liquid–liquid microextraction and CE with UV detection for the chiral separation and determination of the multiple illicit drugs on forensic samples

A new method was developed for pre-concentration, chiral separation and determination of multiple illicit drugs on forensic samples using dispersive liquid-liquid microextraction (DLLME) and capillary electrophoresis (CE) with Ultra Violet (UV) detection. The method was based on the formation of tiny droplets of an organic extractant in the prepared sample solution using water-immiscible organic solvent (chloroform) dissolved in water-miscible organic dispersive solvent (isopropyl alcohol). The organic phase, which extracted heroin, DL-methamphetamine, DL-3, 4-methylenedioxymethamphetamine and dl-ketamine from the prepared sample solution, was separated by centrifuging. The sedimented phase was transferred into a small volume CE auto-sampler vial with 10 μL of 1% HCl methanol solution and evaporated to dryness. The residue was reconstituted in lidocaine hydrochloride aqueous solution (internal standard) and introduced by electrokinetic injection into CE. Parameters affecting extraction efficiency were investigated and optimized. Under optimum conditions, linearity of the method was 0.15-6500 μg/L for all target analytes. The LODs (S/N=3) were 0.05-0.20 μg/L. Excellent repeatability (RSD ≤ 4.4%, n=5) was achieved. The feasibility of this method was demonstrated by analyzing spiked forensic samples. To our knowledge, it is the first time to combine DLLME with CE for chiral separation and determining illicit drugs on forensic samples.