Negative Ion Chemical Ionization- Gas Chromatographic–Mass Spectrometric Determination of Residues of Different Pyrethroid Insecticides in Whole Blood and Serum Atmakuru Ramesh; Perumal E. Ravi
Abstract: A new rapid and sensitive analytical method using negative ion chemical ionization-gas chromatography–mass spectrometry in selective ion monitoring mode has been developed for the determination of residues of different synthetic pyrethroid insecticides, allethrin, bifenthrin, cypermethrin, cyphonothrin, cyfluthrin, l-cyhalothrin, deltamethrin, fenvalerate, fenpropathrin, permethrin, prallethrin, and trans-fluthrin, in whole blood. The residues of pyrethroid molecules were extracted from the whole blood using a hexane and acetone (8:2, v/v) solvent mixture without separating the serum. The method was found sensitive to detect the residues of pyrethroids up to the level 0.2 pg/mL. Experiments conducted with the whole blood samples at the fortification level 1–100 pg/mL showed 91–103% recovery, whereas blood serum samples collected after the fortification of pyrethroids in whole blood showed 36–54% recovery. Recovery experiments conducted by direct fortification of pyrethroids in blood serum samples showed 96–108%. The applications of the analytical method was tested by analyzing 73 human blood samples collected from the population exposed continuously to different pyrethroid-based formulations. None of the blood samples showed residues of pyrethroids. The results were also confirmed by the detection of the appropriate amounts in a number of these samples, which had subsequently been spiked with known quantity of pyrethroids.
Characterization of Gas Chromatography-Negative Ion Chemical Ionization Mass Spectrometry for Ambient Measurement of PAN: Potential Interferences and Long-Term Sensitivity Drift Hiroshi Tanimoto，et al.
Abstract： Gas chromatography/negative ion chemical ionization mass spectrometry (GC/NICI MS) is characterized, elucidating instrument performance for the continuous measurement of peroxyacetyl nitrate (PAN) and its homologues. Chromatograms and linear response at parts per trillion by volume (pptv) levels are examined to evaluate the accuracy of calibration using 4 types of base gases: dry nitrogen, dry synthetic air, purified compressed air, and thermally PAN-decomposed air. The sensitivity to PAN is further checked against humidity, which may be a source of interference in ambient measurements. The experimental results indicate that oxygen, water vapor, and other trace gases in ambient air do not affect the PAN sensitivity. Although significant sensitivity drifts were observed during the course of measurements made at a remote site in Japan, this problem was overcome by performing frequent calibrations with isopropyl nitrate (IPN).
我的社区
签到
赛默飞实验室产品焕新计划有奖调研！
【七月征文】不一YOUNG实验“猿”
报名开启：ICS2024第十三届光谱网络会议！
推荐收藏！盘点中药材及饮片检测解决方案
