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A novel, simple and economic Reverse Phase High Performance Liquid Chromatography (RP-HPLC) method has been developed for the quantification of Amoxicillin (AMX) in bulk and tablet dosage form with greater precision and accuracy. Separation was achieved on Hypersil ODS C18 (250mm×4.6×5micron) column in isocratic mode with mobile phase consisting of Acetonitrile: 0.2M Potassium dihydrogen phosphate buffer (pH 5) (1:99v/v) and conditions optimized with flow rate of 1 ml/minute and wavelength of detection at 254 nm. The retention time of Amoxicillin (AMX) was found to be 6.992 min. The method was validated as per ICH guidelines. Linearity was established for Amoxicillin (AMX) in the range0.6 – 3.4 μg / ml with R2 value 1. The percentage recovery of Amoxicillin (AMX) was found to be in the range 98.87-99.87 %. The high recovery and low relative standard deviation confirm the suitability of the proposed method for the estimation of the drug in bulk and marketed dosage form. Validation studies demonstrated that the proposed RP-HPLC method is simple, specific, rapid, reliable and reproducible for the determination of Amoxicillin for Quality Control level.

Pigments are widely distributed in sugarcane plant cells and have been associated with color in sugarcane juice for white sugar production. Chlorophylls, phenolics and flavonoids compounds are some of those pigments. Mechanized harvesting increases the adding of cane tops to processing and the study of these compounds allows us to understand their impact on the final product. The aim was to separate and quantify these compounds obtained from sugarcane top ethanolic extracts. The chromatographic occurred in adsorption resin. The quantification was made in spectrophotometric systems. These methods allow separation and quantification of compounds and even observation of polarities of molecules compared to the eluents.

The purpose of the study was to isolate and identified the alkaloids fractions local plants in Malaysia. TLC of alkaloid extracts from the plants used in this study revealed the presence of these compounds by using Dragendroff’s reagent to reveal characteristic orange bands of alkaloids. IR spectra of alkaloids extract from the fruit of M. citrifolia, leaves of A. squamosa, and the roots of A. Angustiloba exhibited a strong O-H from the fruit of M. citrifolia. C-H stretching groups are shown for the fruit of M. citrifolia, the leaves of A. squamosa as well as the roots A. angustiloba. The N-H groups are showed in the fruit of M. citrifolia and the root A. angustiloba. The C=O bond at the leaves of A. squamosa and the roots of A. angustiloba. C-H group bonds were detected for the fruit of M. citrifolia, the leaves of A. squamosa and the roots of A. angustiloba. It could be concluded that the alkaloids of the plants can be a new source of antimicrobials against pathogenic bacteria and antioxidant source.

Cereal samples fortified with folic acid obtained in the metropolitan area of Monterrey were analyzed by a chromatographic method developed in our laboratory. The results were compared with the product´s label nutritional information. All tested cereal samples matched the folate labeled. The chromatographic method applied is quick, simple, low cost and suitable for cereal folic acid determination.

Various methods were developed and validated for the analysis of Polycyclic Aromatic Hydrocarbons (PAHs), in the environmental samples. However, their analysis in relevant concentrations in environmental samples can be a challenging task. The aim of this study was to estimate the performance of a modified standard procedure for the determination of polycyclic aromatic hydrocarbons in environmental water samples using liquid-liquid extraction as a preparation step followed by gas chromatography/mass spectrometry. Implementation of long term quality control procedures after validation of the analytical procedures enables acquisition of accurate and reliable results. Three year monitoring of the quality control samples (containing 10-40 ng/L of PAHs) showed that method main characteristics, such as accuracy, precision and measurement uncertainty have constant stability and with no statistically significant changes during this period.

The past decade has seen a large global interest in the development of renewable energy sources, and bio-products based on plant biomass. This is owing to the abundance of lignocellulosic material on the planet and due to their high sugar content. However plant biomass is a complex matrix of hemicellulose and aromatic lignin interacting with core cellulose making it remarkably resistant towards enzymatic saccharification

Agomelatine is a melatonergic antidepressant approved for marketing in the European Union in February 2009; several methods are published for its determination in human specimens so far based mainly on mass spectrometric detection. Aim of this study is the development and validation of the first method based on UV detection of agomelatine after purification from human plasma / serum with a conventional SPE (onto a Bond Elut Certify cartridge) and separation by a UHPLC system (on a Hypersil GOLD analytical column by a mixture of eluents used in gradient mode). The wavelengths of 230 nm and 245 nm were used for the determination of agomelatine and the internal standard (harmine), respectively. The method was validated according to FDA guidelines. Linearity ranges from 50-800 ng/mL, covering therapeutic and supra-therapeutic levels. Extraction recoveries were 91 and 83% for plasma and serum respectively (R2> 0.9946). The intra-day and inter-days precisions ranged from 4.52-7.63 and 5.25-8.01% and, 9.27-10.15 and 9.53-11.05% for plasma and serum, respectively. LODs and LOQs were 15 and 50 ng/mL for both matrices. Overall, the method is specific for agomelatine, selective towards several antipsychotics, other antidepressants and sedative-hypnotics. Validation studies demonstrated that the proposed UHPLC method meets satisfactory validation criteria, is simple, rapid, reliable, reproducible and easily applicable for routine clinical casework.

An improved, Liquid-liquid Extraction (LLE) procedure, without derivatisation, using large volume injection, followed by separation with Gas Chromatography (GC), and mass spectrometric detection, in Selected Ion Monitoring (SIM), has been fully validated and applied in the quantitation of three priority female steroid estrogens (natural estrogens: 17-β-estradiol (E2), estrone (E1) and the synthetic estrogen:17-α-ethinylestradiol (EE2)), in water and in raw influent wastewater matrix. The method has been validated, over the range 10-100 µg/L, showing, for all target analytes, good linearity (mean r2 = 0.997), recovery (mean = ± 99%), and precision (mean RSD = ± 5.5%) in both water and wastewater matrix. The Method Detection Level (MDL) was: 5 ng/L for E1, 2 ng/L for E2 and 5 ng/L for EE2. The LOQ was 10 ng/L for E1, E2 and EE2. The signal/ Noise (S/ N) ratio method gave an LOD and LOQ of 1 ng/L (S/ N = 17-61) for all three estrogens. The method was successfully applied to the determination of the target estrogens in raw wastewater, treated wastewater and river water. The estrogen levels, in all tested matrices, obtained by the GC-MS method compared fairly well with the previously used Enzyme-Linked Immunosorbent Assay (ELISA). The method showed to be a viable option to ELISA and Liquid Chromatography- tandem Mass Spectrometry (LC-MS/MS).

This study shows a method for the detection and quantification of six volatile nitrosamines, dimethyl nitrosamine, diethylnitrosamine, N-nitrosopyrrolidine, N-nitrosopiperidine, N-nitrosomorpholine, N-nitrosoibuthylnitrosamine in meat products. The procedure based on: (a) Isolation of the compounds by vacuum steam distillation, (b) extraction in solid phase - SPE - from aqueous distillates using activated carbon and (c) analysis by gas chromatography-mass spectrometry. The recovery of the compounds from fortified samples (sausages and their preserved liquid) with 200 µg.Kg-1 ranged between 10.9 - 61.7% to solid sample and 20.9 - 80.4% to liquid sample. The direct application of this method to samples of canned sausages allowed the separation, identification and quantification of the nitrosamines at the µg.Kg-1 level with detection limit varying between 0.2 to 1.0 µg.Kg-1.

A simple and rapid reversed phase HPLC method was developed and validated for estimation of pregabalin from the surfaces of equipment used for pharmaceutical manufacturing. The chromatographic separation was achieved on Waters Symmetry Shield RP18 column (5.0 µm, RP18, 250 mm x 4.6 mm) at 40°C by using isocratic elution using methanol and sodium di hydrogen phosphate monohydrate buffer (pH adjusted to 6.30 with NaOH solution; 0.01M) at flow rate of 0.8 ml/min. UV detection was performed at 200 nm. Water was used as swabbing solvent to extract the drug residues from the stainless steel surface. Texwipe swabs (polyester swab) were used to remove the drug from the stainless steel surface. The method was validated for system suitability, specificity recovery, limit of detection, limit of quantification, linearity, ruggedness and robustness. The recovery values from stainless steel surface were found more than 93.5%. The limit of detection and limit of quantification were 0.20 µg/ml and 0.39 µg/ml respectively. Method was found precise at concentration level 0.3917 µg/ml. Method was found linear from 0.39 µg/ml to 2.7979 µg/ml. The coefficient of correlation was observed 0.9999.

The purpose of this study was to isolate and characterize alkaloids from the leaves of Alstonia macrophylla collected from Penang Island, Malaysia. Various chromatography methods, namely thin layer chromatography, column chromatography and centrifugal chromatography were used to isolate and purified extract. Identification of the isolated pure alkaloids was based on their spectral data and various spectroscopic methods. A total of 19 alkaloids were isolated, 15 alkaloids were characterized; the remaining four alkaloids were suspected as new derivative and subjected to be further elucidated. Eight out of 15 alkaloids isolated were varied with alkaloids reported in East Coast, Malaysia studies.

In the present study, a new and simple direct chiral HPLC method was developed and validated for the simultaneous enantiomeric separation of ezetimibe and tramadol. The enantiomeric separation was carried on Chiralpak-ASH analytical column (150 x 4.6 i.d mm, 3 µm) by using acetonitrile: methanol: diethyl amine: formic acid (99/1.0/0.1/0.1% v/v/v/v) as mobile phase. Solvent mixtures were delivered at a flow rate of 1.0 ml/min and peaks were detected at 225 nm. The retention time of R-EZT, S- EZT and S-TRA, R-TRA was found to be 2.12, 2.40 and 4.01, 4.50 min respectively. The calibration curve were plotted in the range of 2.0-10 µg/ml for R-EZT, S- EZT and 1.0-5.0 µg/ml for S-TRA, R-TRA respectively. The proposed method was validated as per the ICH guidelines and found to be specific, linear, selective, and precise. The obtained results indicated that the proposed method can be utilized for the simultaneous enantiomeric purity determination of ezetimibe and tramadol in active pharmaceutical ingredient and their pharmaceutical formulation.

The Piper caldense is a medicinal plant widely used to treat snake bites, as a sedative and for tooth pain. However, there are few reports about the biological potential of the plant and only two reports on its chemical composition. The objective of the present work was to determine the antimicrobial activity and chemical profiles of P. caldense tissues as well as to isolate their major compounds. The major compound 3-geranylgeranyl-4 hydroxybenzoic acid found in all plant tissues, showed antibacterial activity for all tested bacteria including those gram-positive and gram-negative, and especially against gram-positive Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis with minimum inhibitory concentration of 39.5 µg/mL. The compound was characterized based in the interpretations of spectra data of IR, MS, 1H and 13C NMR analysis and chemical profiles of plant tissues obtained by HPLC.