A stimulate method for determination of polybrominated diphenyl ethers ( PBDEs) and derivatives (OH-PBDEs and MeO-PBDEs), tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) in egg samples was developed by gel permeation chromatography ( GPC) and dispersive solid phase extraction ( DSPE) combined with liquid chromatography tandem mass spectrometric ( HPLC-MS/MS) and gas chroma-tography-negative chemical ionization mass spectrometry ( GC-NCI/MS ) . The analytes were extracted with mixture of hexane and dichloromethane (1∶1, V/V) by accelerated solvent extraction (ASE), and purified by 100 mg C18 dispersive solid phase extraction ( SPE) sorbents followed with gel permeation chromatography (GPC) , and then analyzed by liquid chromatography tandem mass spectrometric (HPLC-MS/MS) and gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS), respectively. The quantita-tion was carried out external standard method. The recoveries of objects were 64. 5%-97. 2% and 65. 6%-109 . 2% ( except BDE85 was 54 . 8%, OH-BDE-137 was 47 . 4%) spiked at 1 . 0 μg/kg or 5 . 0 μg/kg in egg white and egg yolk, respectively. The relative standard deviations (RSDs) were less than 20. 2%. The limits of quantitation (LOQ) for the object were 0. 01-0. 2 μg/kg.

Balancing the risks and benefits of organophosphate pesticides(OPs)on human and environmental health relies partly on their accurate measurement.A highly sensitive fluorescence anti-quenching multi-residue bio-barcode immunoassay was developed to detect OPs(triazophos,parathion,and chlorpyrifos)in apples,turnips,cabbages,and rice.Gold nanoparticles were functionalized with monoclonal antibodies against the tested OPs.DNA oligonucleotides were complementarily hybridized with an RNA fluorescent label for signal amplification.The detection signals were generated by DNA-RNA hybridization and ribonuclease H dissociation of the fluorophore.The resulting fluorescence signal en-ables multiplexed quantification of triazophos,parathion,and chlorpyrifos residues over the concen-tration range of 0.01-25,0.01-50,and 0.1-50 ng/mL with limits of detection of 0.014,0.011,and 0.126 ng/mL,respectively.The mean recovery ranged between 80.3％and 110.8％with relative standard deviations of 7.3％-17.6％,which correlate well with results obtained by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The proposed bio-barcode immunoassay is stable,reproducible and reliable,and is able to detect low residual levels of multi-residue OPs in agricultural products.