ABSTRACT
OBJECTIVE： To establish a method for the determination of 33 kinds of pesticide residues in Panax ginseng C.A.Mey by GC-MS/MS and LC-MS/MS. METHODS： The 53 chemical monomers of 33 pesticide residues clearly prohibited by the Chinese ministry of agriculture were selected as the detection indicators. The samples were extracted with acetonitrile by high speed homogenizer. An LC-MS/MS analysis was performed on a CORTECSTM UPLC C18(2.1 mm×150 mm, 1.6 μm) column with isocratic elution of 0.1% formic acid (containing 5 mmol•L-1 ammonium formate) is mobile phase A, 95% acetonitrile(containing 5 mmol•L-1 ammonium formate and 0.1% formic acid)is mobile phase B.Electrospray ionization(ESI)source was applied by positive ionization in multiple reaction monitoring(MRM)modes. GC-MS/MS analysis was performed on a DM17ms(30 m×0.25 mm, 0.25 μm)capillary column with electron impact(EI)source, electron impact (EI) source was applied by positive ionization in multiple reaction monitoring modes (MRM). RESULTS: The correlation coefficient r of 33 pesticide residues showed good linearity in the linear range of 2 to 20 ng•mL-1 was greater than 0.990 0. The average recoveries at spiked levels of low level and high level (0.01 and 0.04 mg•kg-1), repeat 5 times per level. The average recovery was 87.57%-120.98%, and the RSD was between 1.45%-14.03%. CONCLUSION： The method can quickly and effectively detect pesticide residues in ginseng.
ABSTRACT
@#Pesticides application is essential in protecting crops and increases their productivity. However, this causes the pesticide residues to contaminate the crops and their surrounding environment that will eventually lead to exposure to human being. There is very little understanding on the human health effects of pesticides, thus many studies are being carried out for this purpose. In conjunction to this, there are various analytical methods on multi-residue pesticides analysis that have been developed over the years in various samples. This review provides an overview of the reported concentration of pesticides, the extraction and determination techniques of pesticides in environmental samples and the potential health effects they imposed on human in Malaysia from 2007 to 2017.
ABSTRACT
<p><b>OBJECTIVE</b>To develop a rapid multi-residue assay for detecting 16 demanded by the European Union (EU).</p><p><b>METHODS</b>A recombinant penicillin-binding protein (PBP) 2x* from Streptococcus pneumoniae R6 was expressed in vitro and six β-lactams were conjugated to HRP by four methods. A rapid multi-residue assay for β-lactams was established with PBP2x* and HRP-conjugate.</p><p><b>RESULTS</b>PBP2x* was expressed and purified successfully and the ideal HRP-conjugate was identified. The multi-residue assay was developed. After optimization, penicillin G, ampicillin, amoxicillin, cloxacillin, dicloxacillin, oxacillin, nafcillin, cephalexin, ceftiofur, cefalonium, cefquinome, cefazolin, cefoperazone, cephacetrile, and cephapirin can be detected at levels below MRL in milk with simple pretreatment.</p><p><b>CONCLUSION</b>This assay developed can detect all 16 β-lactams demanded by the European Union (EU). The whole procedure takes only 45 min and can detect 42 samples and the standards with duplicate analysis.</p>