200 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.

The invention relates to a GC-MS / MS (gas chromatography-tandem mass spectrometry) method for analyzing dinitroaniline pesticide residue in tobacco and a tobacco product, which is characterized by comprising the following steps: drenching a sample with water, and adding acetonitrile and an internal standard substance; performing vortex extraction and salting-out stratification, and performing secondary salting-out and liquid-liquid extraction with a sodium chloride water solution and n-hexane; and taking the n-hexane supernatant, and determining according to a GC-MS / MS method. The method provided by the invention simplifies the existing sample treatment method, provides a cleaner on-machine solution, and reduces the maintenance of instruments in the operating process. The sample pretreatment process of the method provided by the invention omits a purification step of substrate d-SPE (dispersive solid phase extraction); and instead, the acetonitrile extracting solution is taken, and liquid-liquid extraction and secondary salting-out are performed by using the n-hexane and the sodium chloride water solution, so that the polar coextraction substrate in the supernatant is greatly reduced. By using GC-MS / MS having high sensitivity and high interference rejection, the detection limit of a target substance can be greatly reduced, and the advantages of high sensitivity and favorable repetitiveness are achieved.

The invention relates to a GC-MS / MS (gas chromatography-tandem mass spectrometry) method for analyzing pyrethroid pesticide residue in tobacco and a tobacco product, which is characterized by comprising the following steps: drenching a sample with water, and adding acetonitrile and an internal standard substance; performing vortex extraction and salting-out stratification, and performing secondary salting-out and liquid-liquid extraction with a sodium chloride water solution and n-hexane; and taking the n-hexane supernatant, and determining according to a GC-MS / MS method. The method provided by the invention simplifies the existing sample treatment method, provides a cleaner on-machine solution, and reduces the maintenance of instruments in the operating process. The sample pretreatment process of the method provided by the invention employs the step of drenching the sample with water in the existing method to improve the extraction effect of the acetonitrile on a pesticide target substance, and simultaneously omits the step of putting into a refrigerator before adding into a salting-out package. Inspection discovers that most of pyrethroid pesticides are thermostable, so that the pyrethroid pesticides can not be degraded due to heat release caused by the combination of anhydrous magnesium sulfate and water, thus saving the operating time herein.