[Simultaneous determination of 56 organochlorine and pyrethroid pesticides in traditional Chinese medicines by GC coupled with dual-tower and dual-column].

The paper is to report the establishment of a method for the determination of multi-residue organochlorine and pyrethroid pesticides in traditional Chinese medicines (TCMs). Fifty-six pesticides were extracted by high-speed homogenization, and then purified through gel permeation chromatography (GPC) and solid phase extraction (SPE) cartridges. The residues were simultaneously identified and quantified by GC-ECD equipped with dual tower, dual column and two micro-ECD detectors. The analytical performance was demonstrated by the analysis of 3 TCMs samples' extracts, spiked at three concentration levels for each pesticide. In general, the recoveries ranging from 70% to 110%, with relative standard deviations (RSDs) better than 15%, were obtained. The limit of detection (LOD) for most of the targeted pesticides tested was below 0.01 mg kg(-1). The method had good extraction efficiency, purification effect and good reproducibility, which could be applied to the determination of organochlorine and pyrethroid pesticide residues in the routine analysis of TCMs.

Multi-residue analysis of pesticides in traditional Chinese medicines using gas chromatography-negative chemical ionisation tandem mass spectrometry.

In this study, a residue analysis method for the simultaneous determination of 107 pesticides in traditional Chinese medicines (TCMs), Angelica sinensis, A. dahurica, Leonurus heterophyllus Sweet, Pogostemon cablin and Lonicera japonica Thunb., was developed using gas chromatography coupled with tandem mass spectrometry in negative chemical ionisation mode (GC-NCI-MS/MS). NCI has advantages of high sensitivity and selectivity to chemicals with electron-withdrawing groups, and yields low background interference. For sample preparation, QuEChERS (quick, easy, cheap, effective, rugged and safe) was applied. Due to the unique characteristics of TCMs, the clean-up step was optimised by adjusting amounts of primary secondary amine, C18, graphitised carbon black and silica sorbents. Validation was mainly performed by determining analyte recoveries at four different spiking concentrations of 10, 50, 100 and 200 ng g(-1), with seven replicates at each concentration. Method trueness, precision, linearity of calibration curves, lowest calibrated levels (LCLs) and matrix effects were determined to demonstrate method and instrument performance. Among the 107 pesticides tested, approximately 80% gave recoveries from 80% to 110% and < 10% relative standard deviation (RSD). The LCLs for nearly all pesticides were 5 ng g(-1), and as low as 0.1 ng g(-1) for dichlofenthion, endosulfan sulphate, flumetralin, isofenphos-methyl, methyl-pentachlorophenyl sulphide and trifluralin. The results indicate that GC-NCI-MS/MS is an excellent technique for quantitative and qualitative analysis of targeted GC-amenable pesticides at ultra-trace levels, especially in complex matrices such as TCMs.

[An experimental study of immune function effect of rats irradiated with the complex field cure instrument].

The complex field cure instrument is a new medical instrument with which an experiment was carried out. Rats were continuously irradiated by the complex field for 90 days, with a day's total dose of 285.9 M.T.G. while other rats weren't irradiated for control group. The animals were respectively killed at 7d, 14d, 30d, 60d and 90d, and their blood samples were taken for cell and humoral immune analysis. The results show that values of lymphocyte transform rate, soluble receptor (SIL-2R), total hemolytic complement levels (CH50) and immunoglobulin (A.G.) after irradiation are more than those of the control group having proved that the instrument may improve immune function of rats.