| There are rich vitamins, dietary fiber and minerals such as calcium and iron in fruits and vegetables, which is indispensable food in human daily life. With the continuous improvement of residents’ consumption level, fruit and vegetable consumption per capita is increasing sharply, the safety of fruits and vegetables are also put forward higher requirements. The problem of pesticide residues in fruits and vegetables is one of the major factors affecting safety. Long-term intake of pesticides affect the body’s immune system, the light cause various diseases, the severe teratogenic, carcinogenic, mutagenic and even cause death. The problem of pesticide residues in fruits and vegetables not only endangers the health of people in our country, but also restricts the import and export trade of China’s fruit and vegetable products, which becomes a rigorous challenge faced with food safety field. In recent years, many countries have increased pesticide inspection items, the standard of limits of pesticide residues in fruits and vegetables are becoming strict increasingly. Faced with hundreds of pesticide residue detection requirements and lower maximum residue limits(MRL), it is very important to select a kind of high sensitivity, good selectivity, rapid, efficient, multi-residue simultaneous detection technology for residue analysis workers.Gas chromatography-tandem mass spectrometry(GC-MS/MS) and gas chromatography quadrupole time of flight mass spectrometry(GC-QTOF/MS) with high sensitivity and good selectivity is widely used in the field of trace pesticide multi-residues detection. In this paper, based on the strong analysis ability of GC-MS/MS and GC-QTOF/MS, the performance of them for the determination of 208 pesticide residues in fruit and vegetable samples, including apple, orange, tomato and cucumber, were compared comprehensively. Combining with the differences of two instruments structure, their respective characteristic and scope of application in detection of pesticide residues were presented, which provided the reference for the analysis of pesticide residues. The main research results are as follows:(1) The preparation of the 208 kinds of pesticide standards. The 208 kinds of pesticides’ GC-QTOF/MS database is established. The 208 kinds of pesticides’ GC-MS/MS mass spectrometry information are optimized.(2) In order to validate the pre-treatment method, the recovery experiment of both instruments was carried out respectively. At three spiked levels(5.0, 10.0 and 20.0 μg/kg) with five replicates, two kinds of instruments in the detection of 208 kinds of pesticide residues in four kinds of matrices showed good accuracy, stability and reliability. The average recoveries for the majority of pesticides(93.0%) ranged from 70% to 120% in four kinds of matrices with repeatability were below 20%.(3) The performance parameters of the two instruments, such as limits of detection, limit of quantitation, linear ranges, identification points, matrix effects, screening speed and the detection of non-target compounds were evaluated according to a designed experiment. The limits of detection for most of the pesticides by GC-MS/MS and GC-Q-TOF/MS were less than 5.0 μg/kg, which meets the requirements of the pesticide residue limits. Compared with GC-QTOF/MS, GC-MS/MS showed relatively lower limits of detection and wider linear ranges, and its performance was more satisfactory in accurate quantitative analysis due to its superior sensitivity. On the other hand, GC-QTOF/MS provided accurate mass measurement, which was proved to be an efficient analytical tool on the rapid screening and confirmation of a large number of pesticides and non-target compounds. |
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