A solid phase extraction (SPE) and GC-ECD for multi-residues determination of 14 organo-chlorinated pesticides (OCPs) in radix Pseudo-ginseng were introduced. Using n-hexane as extracting solvent and silica gel for clean up of sample extract, with GC-ECD analysis, good separation of 14 OCPs and carbophenothion(IS) was achieved on capillary column coated with poly(5% diphenyl) siloxane. Experiments showed that n-hexane is adequate as extracting solvent(percentage of recovery70% for 13 in total 14 analyses), the LOD was about 0.35 to 1.6 ppb for blank sample spiked with standards. The method has been carried out on 7 samples collected from market for preliminary investigation of its actual OCPs residues. For 14 OCPs being analysed, results showed that all samples to be examined are complied with requirements of MRL in USP 24 or in Eur. P97.We may conclude that those samples were cultivated in less contaminated soils or none of 14 OCPs was still in illegal use
Panax ; chemistry ; Drug Residues ; drugs

OBJECTIVETo determine organochlorine pesticide residue in 9 Chinese herbs.

METHODSThe organochlorine pesticides were extracted from the herbs with mixed solvents of n-hexane and acetone by a solid-phase extraction cartridge Florisil. Capillary gas chromatography was used to separate the samples.

RESULTSGood linearities were obtained for 11 organochlorine pesticides. The average recoveries at two concentration levels ranged from 79.9% to 89.0%,and from 86.3% to 104.8%, with relative standard deviations of 1.8% to 7.1%, respectively and detection limit of 2 g/kg. The residues of the organic pesticides exceeded national standard in Pogostemon cablin and Panax notoginseng.

CONCLUSIONCapillary gas chromatography combined with electron capture detection provides a practical means for detecting organic pesticide residue in Chinese herbal medicines, and the limits of pesticide residues should be formulated in Chinese pharmacopoeia.

Chromatography, Gas ; Drug Contamination ; Drugs, Chinese Herbal ; chemistry ; Hydrocarbons, Chlorinated ; analysis ; Pesticide Residues ; analysis

OBJECTIVETo establish a novel suspension microarray technology for the detection of three kinds of veterinary drug residues: chloramphenicol, clenbuterol and 17-beta-estradiol (CAP, CL and E2).

METHODSThe three conjugates that veterinary drug coupled with bovine serum albumin (BSA) were synthesized and identified by ultraviolet (UV) spectrophotometry and mass spectrum. The veterinary drug conjugates were immobilized on the polystyrene fluorescent microspheres/beads. There were competitive reactions between the veterinary drugs in the aqueous phase and that on the beads for combination with their specific biotinylated monoclonal antibodies. The optimum amount of the veterinary drug conjugates and the antibodies were optimized and selected. The detective standard curves were plotted. The specificity and the unknown samples were also determined by grouping according to different concentrations of the interferes and the samples. Meantime, the different microstructures of the surfaces of the beads were also observed by scanning electron microscope.

RESULTSCouplings were completed between small molecular veterinary drugs and BSA. The amounts of the three conjugates and the antibodies were optimized. The detective standard curves of the suspension array and their corresponding coefficients of determination (R2) were good (R2 > 0.99). The detection ranges of the three veterinary drugs were (40.00 - 6.25) x 10(5) ng/L, (50.00-7.81) x 10(5) ng/L and 1.00 x 10(3) - 7.29 x 10(5) ng/L respectively. Simultaneously, the specific detection of the suspension microarray was excellent and did not indicate significant cross-reactions. Errors between the found and the real are in the range of 8.09% - 17.03%. It can be considered that the relative standard deviations were relatively small. Successful couplings were also directly confirmed by the observation for microstructures of the surfaces of the beads by scanning of electron microscope and laid good foundation for the following responses.

CONCLUSIONThe high-throughput suspension microarray should provide a novel method for multi-analysis of the veterinary drugs and have a wide applicative prospects with simple operation, sensitive, rapid and low cost.

Chloramphenicol ; analysis ; Clenbuterol ; analysis ; Drug Residues ; analysis ; Estradiol ; analysis ; Microarray Analysis ; methods ; Veterinary Drugs ; analysis

OBJECTIVETo determine the pesticide residues in Shengmaiyin.

METHODThe residues were simultaneously identified and quantified by capillary gas chromatography. The capillary column was OV-1701(0. 32 mm x 30 m, 0.5 microm), splitless injection and Agilent 63Ni electron capture detector ECD were adopted. The carrier gas were high-pure nitrogen, the flow rate were 60 mL x min(-1), the injector temperature was 260 degrees C, and the detector temperature was 300 degrees C.

RESULTIt showed a good linear relationship between peak area and pesticide concentration for 11 kinds of pesticides in the detection concentration range. All correlation coefficients were higher than 0.996 2. The average recovery was 83.1% -114.7%.

CONCLUSIONA simple and efficient monitoring method of pesticide residues is established which provides the foundation for the safe use and analysis of Shengmaiyin.

Chromatography, Gas ; methods ; Drug Contamination ; prevention & control ; Drugs, Chinese Herbal ; chemistry ; Pesticide Residues ; analysis ; Reproducibility of Results

OBJECTIVETo explore the status of clenbuterol pollution in swine products in Beijing city in 2002.

METHODSEuropean Union method (EUR 15127-EN Cy2.3) was adopted to examine the samples. Samples were screened by enzyme-linked immunosorbent assay (ELISA) and confirmed by GC-MS. Detected limit of the method was 0.5 micro g/kg. Samples, including lung, liver, pork, kidney and urine of swine, were collected from slaughterhouses, refrigeratories and markets in 11 districts of Beijing.

RESULTSThe results indicated that 185 out of 1 379 samples were positive with an annual positive rate of 13.4%. The highest was 15.7% in lung of swine, followed by urine 15.2% and pork liver 14.0%.

CONCLUSIONRates of detection had decreased from 30.0% to 2.7% during 2002.

Animals ; China ; Clenbuterol ; analysis ; Drug Residues ; analysis ; Food Contamination ; analysis ; Humans ; Meat ; analysis ; Meat Products ; Swine

In our study, 198 types of pesticides in 120 types 333 lots of traditional Chinese medicine (TCM), which were reasonably classified according to its matrix property, were determined by using the pretreatment platform and gas chromatography-mass spectrometry method. As a result, 158 were contaminated with pesticides. However, the content of pesticides in most TCM was very low. In addition, types of pesticides were different in different part of materia medica. In conclusion, the current status of pesticide residues pollutants in TCM was summarized, and the result can provide proof for the formulation of maximum residue limit. The new species of herbs and the new detecting index should be electively monitored in Chinese Pharmacopeia.
China ; Drug Contamination ; prevention & control ; Pesticide Residues ; analysis ; Plants, Medicinal ; chemistry ; Quality Control

Chromatography, High Pressure Liquid ; methods ; Drug Residues ; analysis ; Electrochemistry ; Ethidium ; analysis ; Luminescent Measurements ; methods ; Sensitivity and Specificity

The residue of the pesticides is closely related to the quality and safety of traditional Chinese medicines(TCMs) and has attracted widespread attention at home and abroad.This article analyzed the current status of pesticide residues in TCMs by summarizing the research results of recent years.At the same time,the methods for the detection of pesticide residues in TCMs were summarized,and the domestic and foreign pesticide residue limit standards for TCMs were compared,intending to provide reference and basis for the detection and control of pesticide residues in TCMs.
Drug Contamination ; Drugs, Chinese Herbal ; analysis ; Medicine, Chinese Traditional ; Pesticide Residues ; analysis ; Research

Misuse and abuse of veterinary antimicrobial agents have led to an alarming increase in bacterial resistance, clinical treatment failure, and drug residues. To address these problems, consistent and appropriate dosage regimens for veterinary antimicrobial agents are needed. Pharmacokinetics/Pharmacodynamics (PK/PD) models have been widely used to establish rational dosage regimens for veterinary antimicrobial agents that can achieve effective prevention and treatment of bacterial diseases and avoid the development of bacterial resistance. This review introduces building methods for PK/PD models and describes current PK/PD research progress toward rational dosage regimens for veterinary antimicrobial agents. Finally, the challenges and prospects of PK/PD models in the design of dosage regimens for veterinary antimicrobial agents are reviewed. This review will help to increase awareness of PK/PD modeling among veterinarians and hopefully promote its development and future use.
Anti-Infective Agents ; Bacterial Infections ; Drug Residues ; Humans ; Treatment Failure ; Veterinarians

OBJECTIVETo establish a high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) method for detection of nine penicillin residues in milk.

METHODSThe samples were precipitated with acetonitrile and degreased with n-hexane for pre-processing. The chromatography was performed by reversed-phase HPLC in a C₁₈ column and eluted gradiently on line for 11 min. The mobile phases were water with formic acid (pH 3.1) and acetonitrile-water with formic acid (pH 3.1). By optimizing the mass condition, the method was operated by multiple-reaction monitoring (MRM) and quantitated by external standard calibration.

RESULTSThe standard curves were linear in concentration range of 0.4 approximately 400 μg/L and all nine penicillins showed a good linear relationship in the milk matrix (r>0.990). The detection limit of the method was from 0.1 to 0.8 μg/L while the limit of quantification was from 0.3 to 2.6 μg/L. The average recoveries were higher than 80%. The within-day precisions were less than 8.5%.

CONCLUSIONThe established method is convenient, rapid and accurate and meets the requirement of monitoring penicillin residues in milk.

Animals ; Chromatography, High Pressure Liquid ; methods ; Drug Residues ; analysis ; Milk ; chemistry ; Penicillins ; analysis ; Tandem Mass Spectrometry ; methods