[Determination of bifenthrin residue in plant-based foods using gas chromatography-mass spectrometry].

A method was established for the determination of bifenthrin residue in 8 plant-based foods using gas chromatography-mass spectrometry (GC-MS). The grain was extracted by acetonitrile and cleaned up with gel permeation chromatography (GPC) combined with a Florisil solid-phase extraction (SPE) cartridge, while the vegetables and fruits were extracted by ethyl acetate and cleaned up only with a Florisil SPE cartridge. Most of the lipids in the extract for the grain were eliminated by GPC, prior to SPE cleanup. The cleaned extract was analyzed by GC-MS with electron impact (EI) source in selective ion monitoring (SIM) mode. The detection limit was 5 microg/kg (S/N = 10). There was a good linearity within the range of 0.005 -0.5 mg/L with the correlation coefficient of 0.999 9. The recoveries were between 74% - 99% with the relative standard derivations of less than 13% at the spiking levels of 0.005, 0.04 and 0.1 mg/kg.

[Determination of U, Th and Tl in fourteen Chinese traditional medicines by microwave digestion-ICP-MS].

Fourteen Chinese traditional medicines were digested by microwave digestion, which are generally applied to treat tumor in clinic, and the contents of U, Th and Tl in the fourteen Chinese traditional medicines were determined by inductively coupled plasma mass spectrometry (ICP-MS), and the results show that the change ranges of the elements contents were: 0.005 153-0.1534 microg x g(-1) for U; 0.03501-0.4628 microg x g(-1) for Th; 0.00143-1.600 microg x g(-1) for Tl. The contents of U, Th and Tl in the fourteen Chinese traditional medicines were low, and not with one accord. The determination results of the fourteen Chinese traditional medicines were analyzed by SPSS 11.5, and the results show that there were not significant deviations(p>0.05) of the contents of U, Th and Tl between the medicine of treating the toxifying disease with poisonous agents and the medicines of heat-clearing. The study indicates that inductively coupled plasma mass spectrometry (ICP-MS) is a quick, accurate, sensitive method to determine the contents of U, Th and Tl in Chinese traditional medicine, and the results of this study provide reference data for using Chinese traditional medicine safely in clinic and developing Chinese traditional medicine.

[Determination of Pb, Cd, Hg and As in three sorts of Chinese traditional medicine treating tumor by ICP-MS].

A method was proposed to determine Pb, Cd, Hg and As in three sorts of Chinese traditional medicine treating tumor (Jinkehuaier, Huachansu and Fufangkushen) by ICP-MS. The result shows that the contents of the four elements Pb, Cd, Hg and As in these three sorts of Chinese traditional medicine treating tumor are low, which are all correspond with the import standard in Southeast Asia. The contents of Hg and As in Jinkehuaier are higher than the standard of U.S. FDA about drug and health food. ICP-MS is a quick and accurate method for the determination of Pb, Cd, Hg and As in Chinese traditional medicine.