Methodological support of control of the content of n-nitrozodiphenylamine in food meat and meat/plant products

The methodical methods used in the practice of the development and application of methods for the determination of chemical compounds in food products for practical instrumental studies used in conducting laboratory studies of food safety are considered. An algorithm for the development of a chromatography-mass spectrometric technique for the determination of one of the group of highly toxic, carcinogenic N-nitrosamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosopyrrolidineamin, N-nitrosomorpholinamine, N-nitrosodipropylamine, N- nitrosopiperidinamine N-nitrosoperidineamine and N-nitrosodiphenylamine in homogenized canned meat and meat products (canned meat) is supposed. The algorithm included experimental development of chromium parameters of chromatography-mass spectrometric determination of an analyte, the selection of optimum conditions of sample preparation of samples of canned meat to minimize the influence of the matrix: the transesterification reaction of fatty acids, organic solvent extraction, solid phase extraction, study of extraction completeness by means of the method “introduced – found”, establishment of metrological characteristics of the process of the measurement. The high sensitivity and selectivity of the chromatography-mass spectrometric determination of N-nitrosodiphenylamine in canned meat samples with a lower limit of 0.0002 mg/kg and a maximum error of not more than 23% was achieved owing to the use of a set of methodical techniques — the selection of optimal chromatographic analysis conditions: capillary column series HP-FFAP 50m • 0,320 mm • 0,50 μm, temperature programming of the column: initial temperature of 50ºС, the temperature rise up to 120ºС at a speed of 8 °C/min; from 120° to 185 °C at a rate of 12 °C min and from 185 ° to 240 °C at a rate of 25 °C/min with exposition at a final temperature of 5 minutes; mode of operation of the mass spectrometric detector: selective ion monitoring (SIM) for three characteristic ions of the analyzed compound of 167, 168, 169 m/z. Using the reaction of transesterification of fatty acids contained in canned meat, potassium methylate, removal of the formed esters from samples of canned meat with an organic solvent (hexane), concentration of N-nitrosodiphenylamine in the aqueous layer on cartridges of an automatic solid-phase extraction system provides the extraction of N-nitrosodiphenylamine from the test samples by 99.94%. In the process of approbation of the chromatography-mass spectrometric method, the content of N-nitrosodiphenylamine in the concentration range 0.030 ± 0.011 ÷ 3.89 ± 0.83 mg/kg was found in samples of homogenized canned food meat and meat products (canned meat) from various manufacturers. The highest concentration of N-nitrosodiphenylamine C = 3.89 ± 0.83 mg/kg was found in the sample of canned meat «beef + chicken».