| Sodium cyclamate(also known as Sodium cyclamate)has a molecular formula of C6H11NHSO3Na and a relative molecular mass of 201.22.One of the sweeteners as a sweetener is a food additive widely used in the food industry.Liquor in the fermentation process will produce a bitter taste and sweetness that is not conducive to the taste and flavor can cover up this flavor,so there is an illegal addition of cyclamate in the market liquor products to improve the taste of the product although cyclamate is the food allowed in the national standard.Additives,but clearly do not use in liquor.Therefore,the detection of cyclamate content in white wine has become an important project of the food and drug regulatory authorities.Electrospray ionization tandem mass spectrometry has rarely been reported on the specific detection of cyclamate in food testing.The application of this method in food has profound research significance and value;the specific research contents are as follows:(1)Taking liquor as the research object,the electrospray ionization tandem mass spectrometry combined with chemometric calculation was used to investigate the gas phase ion chemical behavior and structure information of cyclamate formed after ionization.The parent ion[C6H11NHS03+H+Na]+occurred SN.The bond breaks to form[C6H11NHS03+Na]+.and the cyclamate m/z=178 is the excimer ion[C6H11NHS03Na-Na]-formed after the Na-removal on the sulfonic acid group in the cyclamate molecule,and m/z=79.9 is cyclamate.The fragment ion[C6H11NHS03Na-Na-C6H11-NH]-formed after the removal of the cyclohexyl group and the secondary amino group,and m/z=95.9 is the fragment ion formed after the cyclohexyl group is removed from the cyclamate[C6H11NHS03Na-Na-C6H11-NH]-Explore its ionization reaction mechanism by changing its structural information.The composition of cleavage fragments of cyclamate in the traditional collision-induced dissociation technology was established,and the structure of ions and protons generated by electrospray collision-induced dissociation technology was analyzed.The theoretical calculation of cyclamate in the cracking collision energy conversion provides a more detailed theoretical basis for speculating the structure of cyclamate and its ionization,and its cracking mechanism during mass spectrometry.(2)Select the range of values corresponding to the single-factor better results,use Box-Behnken response surface for optimization analysis,establish ion source temperature(A),capillary voltage(B),magnetic gas flow rate(C),extract The solvent(D)is an independent variable.A response surface model was established.The model P value<0.0001 indicates that the model reaches a very significant level and the ion source temperature,capillary voltage,magnetic gas flow rate,and extraction solvent have an effect on the recovery rate.The correlation coefficient R2 between the sequence residual and the expected value is 0.998 8,indicating that the response has a good linear relationship,the regression equation model can truly and effectively describe the relationship between various factors and recovery rate,indicating that the regression equation can optimize recovery.Among the factors,the primary items B,C,D and the quadratic terms AC,BC and the squared phase A2.B2,C2 and D2 have significant effects on the recovery rate,which is significant for the recovery optimization.It can be seen from the F value that the order of influence of each factor on the recovery rate of cyclamate is extraction solvent>capillary voltage>magnetic gas flow rate>ion source temperature.(3)The content of cyclamate in liquor was determined by liquid chromatography-mass spectrometry/mass spectrometry with reference to GB5009.97-2016.The results showed that the recovery rate of sodium cyclamate was 89.69-90.44%,which was significantly lower than that of electrospray ionization tandem mass spectrometry(94.55%).The recovery effect,the minimum detection limit of chromatography-mass spectrometry is 10-28 ng/mL,and the minimum detection limit is worse than electrospray ionization tandem mass spectrometry. |
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