Entity

Time filter

Source Type

Nanjing, China

Meng W.,East China University of Science and Technology | Guo Z.,CAS Dalian Institute of Chemical Physics | Shen W.,Food Laboratory | Shen C.,Food Laboratory | And 5 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2012

A simple and efficient method based on a novel solid phase extraction (SPE) cartridge and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS/ was developed for the determination of clenbuterol residue in pork. The minced pork sample was ultrasonically extracted by 5% (v/v) perchloric acid and centrifuged at 10 000 r/min for 15 min, then the supernatant was purified by an SMCX cartridge; which is a novel SPE column based on homemade silica matrix with two mixed modes of reversed-phase and strong cation exchange; for the selective enrichment and purification of the analyte. The linear range of the method was 0.25-50 μg/kg with a correlation coefficient of 0.9982. The average recoveries ranged from 62.2% to 72.0% at the three spiked levels of 1.25, 12.5 and 50 μg/kg with the relative standard deviations (RSDs) between 4.2% and 6.1%. The limit of detection (S/N=3) was 0.05 μg/kg. The method is simple, fast and can be extended to enrich and determine β-agonist drugs. © 2010 Editorial Office of Chinese Journal of Chromatography, Dalian Institute of Chemical Physics, CAS.


Wei X.,China Pharmaceutical University | Wei X.,Food Laboratory | Shen W.,Food Laboratory | Yu K.,Food Laboratory | And 8 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2016

The gas chromatography-mass spectrometric (GC-MS) method with two different ionization techniques, electron impact (EI) and positive chemical ionization (PCI), have been developed for the simultaneous determination of three sterenes in olive oil. The olive oil sample was dissolved in petroleum ether, followed by cleanup on a silica gel column and finally analyzed by GC-EI/MS and GC-PCI/MS in selected ion monitoring mode. The quantitation was performed by internal standard calibration with cholesta-3, 5-diene as internal standard. These two methods were compared in terms of linearity, accuracy, precision and sensitivity. Good linearities were obtained with correlation coefficients (r) higher than 0.999 for campesta-3, 5-diene in the range of 0.024 to 0.48 mg/L, stigmasta-3, 5, 22-triene in the range of 0.02 to 0.50 mg/L and stigmasta-3, 5-diene in the range of 0.03 to 0.75 mg/L. The accuracy test was carried out at three spiked levels in extra virgin olive oil. The average recoveries ranged from 88.7% to 99.5% (EI) and 87.1% to 109.2% (PCI), with relative standard deviations (RSDs, n=6) not higher than 8.3%. Limits of quantification (LOQs, S/N=10) were 0.03 mg/kg (EI) and 0.03-0.10 mg/kg (PCI). Comparative analysis showed a large number of fragment ions could be obtained in EI mode while quasi-molecular ions or other adduct molecular ions were the most abundant ion formed in the PCI mode. Besides, PCI has a better selectivity than EI when applied to real samples. In conclusion, these two ionization techniques are complementary and alternative in the routine analysis of sterenes in olive oil.


Xia G.,China Pharmaceutical University | Shen W.,Food Laboratory | Yu K.,Food Laboratory | Wu B.,Food Laboratory | And 5 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2014

A method was developed for the determination of four insecticide residues in honey and royal jelly by gas chromatography-negative chemical ionization mass spectrometry (GC- NCI / MS). The honey and royal jelly samples were treated with different preparation methods as the result of the different components. The honey sample was extracted with ethyl acetate and cleaned up with primary second amine, and the royal jelly sample was extracted with acetonitrile-water (1 :1, v / v), and cleaned up with a C18 solid-phase extraction column. Finally, the extracts of the honey and royal jelly were analyzed by GC-NCI / MS in selected ion monitoring (SIM) mode separately. External standard calibration method was used for quantification. The linearities of calibration curves of the four insecticides were good with the correlation coefficients greater than 0. 99 in the range of 50-500 μg / L. The limits of the detection (LODs) of the four insecticides were in the range of 0. 12-5. 0 μg / kg, and the limits of the quantification (LOQs) were in the range of 0. 40-16. 5 μg / kg. The recoveries of the four insecticides spiked in honey and royal jelly at three spiked levels (10, 15 and 20 μg / kg) were in the range of 78. 2% -110. 0%, and the relative standard deviations (RSDs) were all below 14%. The sensitivity and selectivity of this method were good with no interfering peaks. The proposed method is simple, quick and effective to analyze the four insecticide residues in honey and royal jelly.

Discover hidden collaborations