water contamination due to the wide variety of pesticides used in agriculture is a global environmental pollution problem. in order to reach at sub-î¼gl-1 levels of detection, an efficient extraction technique is required. a simple, fast and economical method, dispersive liquid-liquid micro extraction (dllme), followed by gas chromatography-mass spectrometry was assessed for determining endosul...

The aim of this study was the development and validation of a new method for carbohydrates analyses obtained from woody biomass, as a step of bioethanol production. In this study, we have quantified carbohydrates in wood by gas chromatography (GC) after derivatization. Quantification of carbohydrates was made by liquid-liquid extraction, oximation and silylation and, finally, analysis by gas ch...

The aim of this study is to evaluate the bioactive compounds in the ethanolic leaf extract of Azima tetracantha by using Gas chromatographyMass Spectrometry (GCMS). Azima tetracantha leaves were collected from Ariyalur District, Tamil Nadu. The dried leaf powder was extracted with the solvent ethanol by using Soxhlet apparatus. One microlitre of the extract was subjected for analysis by GCMS to...

194 CLINICAL CHEMISTRY, Vol. 25, No. 1, 1979 gas chromatography before and after acid (6 mol/L HC1) and alkaline (NaOH) hydrolysis. We frequently observe a peak in the lactic acid position after alkaline hydrolysis. After acid hydrolysis of the same urine no lactate isobserved, but a peak appears in the position of levulinic acid. The mass spectra of these two peaks were identical with those of...

The aim of this work was to study the biodiesel production from cotton seed oil by lipase produced by Pichia guilliermondii lipase, which was immobilized onto hydrophobic magnetic particles (HMPs). The optimum reaction conditions were determined for lipase dosage, methanol-to-oil molar ratio, temperature and water content. Using response surface methodology, a quadratic polynomial equation was ...

[1] As part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA)Cooperative LBA Airborne Regional Experiment (CLAIRE) 2001 campaign in July 2001, separate day and nighttime aerosol samples were collected at a ground-based site in Amazonia, Brazil, in order to examine the composition and temporal variability of the natural ‘‘background’’ aerosol. We used a high-volume sampler to ...

The conversion of deuterium-labeled ceramide to cerebroside has been studied. A mixture of N-(2’+hydroxy [4’,4’,5’,5’-2H4]hexadecanoyl) D-eryfhYO-1,3-dihydroxy-2amino-4-frans-[4,5-*H2]octadecene and N-(2’-D-hydroxy hexadecanoyl) D-eryfhro-l,3-dihydroxy-2-amino-4-frans-[33Hl]octadecene was incubated with mouse brain microsomes and a UDP-galactose regenerating system. Both galactosyl ceramide and...