| In recent years, pesticide residues in traditional Chinese medicine had been concerned wide widely. If absorbed into human body and reaching to a poisonous dose, they impair human's health seriously. Therefore, more and more pesticides and traditional Chinese medicines are required tested, and it is very important to develop and build an analytical method for detecting pesticide multi-residues in Chinese herbal medicines that we can monitor the pesticide residue correctly and keep patients away from dangerous. The article would like to develop and build a quick analytical method to detect organ chlorine, organ phosphorus, pyrethroid, carbamate pesticides in Chinese herbal medicine.By studying factors relating recovery, such as extracting solvent, temperature of ultrasonic extraction, ultrasonic extraction time, and so on, the pre-treatment conditions were established. Firstly, the Chinese herbal medicine powder was extracted by acetonitrile solution of 1% acetic acid. Secondly, ultrasonic extracted for 20 minutes at the temperature of 4 centigrade. Thirdly, extracting solution was purified by solid-phase dispersion and sample solution was obtained.The experiments were performed on a DB-17MS capillary column (30m×0.25mm×0.25μm) with a temperature programming which is initial temperature 60℃for 1 minute, then heating to 130℃by the rate of 30℃/min, then to 200℃by 10℃/min, then to 237℃by 1.4℃/min, then to 241℃by 2℃/min, then to 243℃by 1.4℃/min, then to 249℃by 3℃/min, finally to 300℃by 12℃/min for 17.6 min. The Inlet temperature was 290℃, column flow 1.0mL/min, splitless injection with inpouring 1.00μL. The mass spectrum was recorded using El source, with electron energy at 70eV, in selected ion monitoring mode, transmission line temperature at 280℃, ion source temperature at 230℃, quadruple temperature at 150℃.The study results showed that 53 pesticide residues could separate from each other in selected ion monitoring mode, good linearity within test range of 0.01～31.00 mg/L for 53 pesticide residues, with the correlation coefficients of all linear equations above 0.99. The lowest limit of detection was 0.003～0.312 ng, and the lowest limit of quantification was 3.3～123.3μg/kg. The RSD of within-day precision was all smaller than 10.52%, and the RSD of day to day precision was all smaller than 5.98%. The RSD of intradaily stability was between 0.55% and 5.94%, and the RSD of interdaily stability was between 0.27% and 5.98%. When spiked in the range of 3.3～493.2μg/kg, the recoveries were 76.15～109.81%; When spiked in the range of 6.7～986.4μg/kg, the recoveries were 74.3～105.3%; When spiked in the range of 13.2～1972.8μg/kg, the recoveries were 79.2～105.1%. The result of the method validation suggests that the method is simple, quick and precise, and suitable for detecting pesticide multi-residues in the Chinese herbal medicines quickly.There were 16 pesticide residues detected by the method when applied in the following Chinese herbal medicines, including Radix Glycyrrhizae, Radix Scutellariae, Flos Lonicerae, Radix Notoginseng, Radix Sophorae Flavescentis, Rhizoma Gastrodiae, Radix Astragali, Radix Ginseng, Cortex Phellodendri. Among the 16 detected residues, there were 8 pesticides which were alpha-BHC, gamma-HCH, o, p'-DDT, p, p'-DDE, p, p'-DDT, Fenvalerate, Cypermethrin and Methidathion on the list of "Need to detect pesticide" of ChP (2005 edition), While another 8 pesticides, which were p, p'-DDD, Chlordane, Trans-heptachlor epoxide, Aldrin, Cis-heptachlor epoxide, Isofenphos-methy Phorate and Triazophos, were not on the list of "Need to detect pesticide" of ChP (2005 edition). DDT residues in Radix Glycyrrhizae (1D) and Aldrin residues in Radix Sophorae Flavescentis (5C) exceeded South Korea Pharmacopoeia standards, and Isofenphos-methyl and Phorate were forbidden to be used in Medicinal plants.It was time-consuming that ChP (2005 edition) used three pre-treatment conditions and three instrumental analysis methods detecting 24 pesticide residues in Chinese herbal medicines. The article developed a quick method detecting 53 pesticide residues in Chinese herbal medicines at the same time, supplying referring informations for Chinese herbal medicine exporting and more standards of pesticide limit establishing. |
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