201 results about "Gas Chromatography/Tandem Mass Spectrometry" patented technology

A gas chromatography-mass spectrometer (GC-MS) / MS measuring method for 20 pesticide residues in tobaccos and tobacco products is characterized by comprising adding acetonitrile and an internal standard substance after a to-be-measured sample is soaked by water, then performing vortex extraction and salting-out layering, adding toluene to perform liquid-liquid extraction, taking supernatant to perform dispersive solid-phase extraction (d-SPE), and using a GC-MS / MS method to perform measurement. The method has the advantages that the water is utilized to soak the sample, and extraction effects of organic solvent acetonitrile added later on on pesticide targets are improved; freezing treatment is performed in advance before anhydrous magnesium sulfate is added, so that thermal degradation of part of the targets caused by severe heat release of anhydrous magnesium sulfate in the dewatering process is avoided; toluene is added in the sample extract liquid after extraction salting-out, the obtained extract liquid has shallower color than when acetonitrile is independently used, and the effects of diluting the extract liquid and partially removing impurities for the extract liquid are achieved actually.

The invention discloses a GC-MS / MS (Gas chromatography-tandem mass spectrometry) method for simultaneously analyzing three polycyclic aromatic hydrocarbons and four tobacco-specific nitrosamines in main stream smoke of cigarettes. The method comprises the following steps of: taking out a Cambridge filter disc catching granule phase objects of main stream smoke of cigarettes, adding ethyl acetate and an internal standard, carrying out vibrating extraction, carrying out dispersive solid-phase extraction (d-SPE) on extracting liquid, then, carrying out nitrogen-blowing concentration on supernatant, and measuring by using GC-MS / MS. The method provided by the invention overcomes the problems that a sample treatment method can separately detect the two substances in the prior art and the pretreatment is tedious; and a sample pretreatment method and an instrument detection condition are optimized aiming at the granule phase objects of main stream smoke of cigarettes. The method provided by the invention has the advantages that two target objects with large polar phase differences are extracted at the same time by 10mL of ethyl acetate, and the extraction efficiency is high; and compared with the national standard method, the method has the advantages that the consumption of an organic solvent is reduced by a several times to tens of times, and the method has the characteristics of accurate operation, high sensitivity and good repeatability.

The invention discloses a GC-MS / MS (Gas Chromatography-Mass Spectrometer) / MS (Mass Spectrometer) method for simultaneously analyzing four tobacco-specific nitrosamines (TSNAs) in main stream smoke of a cigarette. The method is characterized by comprising the steps of: adding ethyl acetate and an internal standard substance after taking out a Cambridge filter on which main stream smoke particulate phase substances are captured; getting an extract liquor after vibrating extraction and carrying out dispersive solid-phase extraction (d-SPE) on the extract liquor; then getting the supernatant liquor and carrying out nitrogen flushing concentration on the supernatant liquor; and measuring by a GC-MS / MS method. According to method disclosed by the invention, the shortcoming of complex treatment an existing method is overcome, and the pretreatment method of a sample and the instrument detection conditions are optimized aiming at the main stream smoke particulate phase substances in the cigarette. Compared with the prior art, the method disclosed by the invention has the following good effects that four TSNAs are simultaneously extracted by using ethyl acetate in pretreatment of the sample, so the good extraction efficiency is realized. Compared with the national standard method, the method disclosed by the invention has the effect that the use amount of organic solvent can be reduced by tens of times (260ml of dichloromethane is needed for measuring the TSNAs according to the national standard), and has the advantages of accuracy in operation, high sensitivity and good repeatability.