RESUMO
A novel method was developed for the direct analysis of testosterone, androstenedione, methyltestosterone and methenolone in serum samples by fully automated online turbulent flow solid phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry. An aliquot of 50 μL serum sample was preconcentrated directly on a Turboflow SPE column after centrifugation. Turboflow SPE C18-P could be used to remove serum matrix effectively. The optimum loading flow rate and elution time were 4. 0 mL/min and 1. 0 min, respectively. The linearity ranges were from 1. 0 μg/L to 100. 0 μg/L for four target compounds. The method limits of detection ( LODs) were in the range of 0. 2-0. 3 μg/L. The relative standard deviations (RSDs) ranged from 2. 9% to 14. 1% (n=5). The time for one sample analysis including extraction, separation and determination was 32 min. The proposed method has been successfully applied for the analysis of serum samples.
RESUMO
Solid phase microextraction(SPME) can be effectively used to extract volatile and semivoltaile organic compounds from different environmental matrix. In this paper, we utilize headspace-SPME technique combined with capillary gas chromatography (CGC) and a laboratory modified flame photometric detector using quartz surfaceinduced luminescence (QSIL-FPD) for analyzing butyltin compounds in sediments. The detection limits of mono-,di-, and tri-butyltin compounds, based on the signal equal to 3 times the baseline noise are 16.9 ng/g, 1.58 ng/g adn 0.17 ng/g, respectively.
RESUMO
A sensitive method for the determination of inorganic mercury and total organomercury in chemical waste water by cold vapor generation-atomic fluorescence spectrometry (CVG-AFS) was proposed. Inorganic mercury was directly determined by CVG-AFS. Organomercury was oxidized by potassium persulfate to its inorganic form prior to analysis. The difference between the two data was the value of total organomercury. Parameters affecting the sensitity in the process for the determination of mercury had been studied and optimized. Detection limit of mercury chloride was 8.2 ng/L.
RESUMO
The organotin compounds in the contaminated lard samples were identified by gas chromatography-flame photometric detector and gas chromatography/mass spectrometry after propylation with Grignard reagent. Experimental results identified that all lard samples contain dimethyltin compound and most of these samples contain tri-and monomethyltin compounds.