Method for measuring residual amount of three types of dithiocarbamate in tobacco

Abstract

The invention discloses a method for measuring the residual amount of three types of dithiocarbamate in tobacco. To-be-tested tobacco powder is processed by an alkali extracting solution and then processed powder is filtered; the filter solution is collected and the analysis is carried out by LC-MS-MS; and then standard curve drawing and calculation are carried out to obtain a result. According tothe invention, the residual amount of three types of DCs materials in tobacco is measured accurately for the first time. The linear range of the three DCs materials is from 20mg / L to 100mg / L; the correlation coefficients of the three DCs materials are not less than 0.99 respectively; the detection limits are 2.3 microgram / kg, 4.3 microgram / kg, and 5.2microgram / kg respectively; the quantitation limits are 7.7 microgram / kg, 14.3 microgram / kg, and 17.3microgram / kg; the matrix effect ranges are from 0.19 to 0.50, from 0.78 to 1.70, and from 0.35 to 0.87; the intra-day RSDs of all DTCs of tobaccomatrixes are from 11.33% to 16.80% and the inter-day RSDs are from 5.84 to 6.54%; and the adding standard recovery is from 84.5% to 103.5%. According to the method disclosed by the invention, the operation becomes simple and convenient; the analysis speed is fast; the accuracy and precision as well as the stability are high; and the quantitative analysis requirement is met.

Description

technical field [0001] The invention belongs to the technical field of tobacco physical and chemical testing, and in particular relates to a method capable of accurately measuring the residual amount of three types of dithiocarbamate in tobacco. Background technique [0002] Dithiocarbamates (DTCs) are organosulfur protective fungicides. It can inhibit the oxidation of pyruvic acid in pathogenic bacteria, thereby playing a bactericidal effect. It is mainly used to prevent and control anthrax, dry blight, root rot, red spot disease or black shank on tobacco. DTCs pesticides are relatively stable on the surface of tobacco leaves, so it is easy to cause residues in tobacco. According to the compound structure, DTCs are divided into three categories, namely: dimethyl dithiocarbamate (DMDC), ethylene bisdithiocarbamate (EBDC), and propylene bis(dithioamino methyl ester) (PBDC). [0003] The prior art mainly uses the carbon disulfide method (including spectrophotometry and gas ...

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Problems solved by technology

[0003] The prior art mainly uses the carbon disulfide method (including spectrophotometry and gas chromatography) to detect dithiocarbamate in freshly cured tobacco leaves and cigarettes, but this method can only measure the total residues of dithiocarbamate Quantity, cannot accurately identify and quantify specific components

[0004] Liquid chromatography-mass spectrometry-mass spectrometry (LC-MS / MS), which combines the high separation ability of LC with the high sensitivity and strong qualitative specificity of MS, can distinguish the different dithiocarbamate species, can carry out qualitative verification and quantification of this type of pesticide, and can make up for the deficiencies of the current industry standards. If this method is applied to the detection of tobacco, it should be able to overcome the deficiencies of the existing detection methods. However, in the prior art No successful reports yet

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