The purpose of this study was to evaluate the effect of copper and silver in the plants on the mining area and the ingredients of essential oils. Plants collected from the same family, but they were collected randomly from various regions. The concentration of heavy metal in plant samples collected from Veshnave, Qom, Iran have been determined by Flame Atomic Absorption Spectrometry (FAAS). The...

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 ...

Suhu kolom Gas Chromatography-Mass Spectrometry (GCMS) merupakan salah satu variabel yang harus diperhatikan pada analisis senyawa kimia, agar terpisahkan dengan baik. Penelitian ini bertujuan untuk menentukan suhu terprogram optimum asam lemak menggunakan instrumen GCMS. Sampel digunakan berasal dari hasil ekstrak mikroalga Chlorella. Ekstrasi Chlorella dilakukan cara sonikasi selama 60 menit ...

Ammonia is a very useful chemical ionization (CI) reagent gas for the qualitative analyses of compounds by positive ion gas chromatography-mass spectrometry (GCMS). The gas is readily available, inexpensive, and leaves no carbon contamination in the MS source. Compounds of interest to our laboratory typically yield abundant protonated or ammoniated species, which are indicative of a compound's ...

The advantages of mass spectrometry (MS) in combination with gas chromatography (GC) – in terms of providing both qualitative and quantitative information are well known. However, confident identification and accurate measurement of trace toxic and odorous species at the lowest levels of interest may be compromised by chromatographic anomalies such as; column bleed, extended solvent tails, air ...

Fourier Transform Infrared (FTIR) and Gas Chromatography Mass Spectrometry (GCMS) are two common instruments used for analysis of edible oils. The output signal is often analysed on the software attached to the workstations. The processing software is usually individualised for a specific source. The output of GCMS cannot be analysed on the FTIR hence analysts often need to juggle between instr...