Establishment Of High Resolution Mass Spectrometry For The Detection Of Pigment And Risk Monitoring Of Easily Dyed Food

Edible synthetic pigment has the advantages of low cost,bright color,strong coloring power,stable property,easy to mix and so on,which is widely used in food processing and production.However,it is found that even synthetic food pigments are harmful.In order to save costs,some illegal enterprises illegally add industrial dyes,which cause more serious harm to human health.The kinds of edible synthetic pigments and industrial dyes are increasing year by year.Food safety problems such as abusing edible synthetic pigments,using unapproved new pigments to avoid standards,and even illegally adding industrial dyes are becoming more and more serious.At present,the detection methods of edible synthetic pigments and industrial dyes are mainly liquid chromatography ultraviolet detection.The same sample needs to be repeatedly determined by different pre-treatment methods and different instruments,resulting in the problems of long analysis time,low sensitivity of the instrument,large interference of the substance to be measured,and large consumption of the laboratory.At the same time,the current detection method can only detect the known target compounds quantitatively,while the detection of unknown targets lacks the ability of screening,leading to the outbreak of problems before supervision,resulting in the lag of food safety supervision.Therefore,in this study,70kinds of pigment accurate quality databases?primary,secondary and isotope distribution databases?were established by using the technology of ultra-high performance liquid chromatography electrostatic field orbital well high resolution mass spectrometry.The databases can be used to screen and confirm the side samples without standards,which can effectively solve the above problems.The main research contents are as follows:?1?Based on literature review and market survey,70 kinds of natural pigments were summarized,which were easy to be abused,illegally added and commonly used.Based on the ultra high performance liquid chromatography electrostatic field orbiter high resolution mass spectrometry technology,electrospray ion source,positive ion and negative ion simultaneous switching scanning mode were used to optimize the liquid chromatography elution gradient program and mass spectrometry acquisition conditions.The retention time,the first order accurate mass number,the two grade fragment exact mass number,and the isotope distribution as the main information were used to establish 70 pigments with high resolution.Spectrum screening database.The fragmentation of typical synthetic pigments such as lemon yellow was studied.It was summarized that decarboxylation lost fragment ions formed by CO₂,forming[M-3Na+H-CO₂]²,followed by cracking of Pyrazolin hydrazone ring C-C,breaking of N-N bond and producing fragmentation fragments.Many sodium salt pigments will form a series of excimer ion peaks of[M-xNa+yH]^?x-y?and have multiple charged forms at the same time.Other pigments usually form The excimer ion peaks of[M+H]⁺?[M-H]^-?[M-Cl]^-are formed.?2?A screening method based on tracefinder software is established.After optimizing the parameter conditions,the sample data can be imported for automatic screening and confirmation;the situation of false negative and false positive is discussed,and a set of screening ideas combined with manual analysis is summarized to ensure the accuracy of screening.At the 0.005 mg/kg level of blank matrix,except for Citrine,chloroanthocyanin,acid orange 92,carminic acid and eosin Y,the rest of blank matrix can be automatically screened and matched by tracefinder,and all of them can be matched by the machine after the extract is concentrated.?3?The extraction efficiencies of methanol/water,acetone/water and acetonitrile/water were compared,and a variety of pretreatment methods with high throughput,high recovery and high recovery were established.The recovery of para red,astaxanthin,anthocyanin and some Sudan pigments was about 50%in methanol:water=1:1,but the recovery of other pigments was in the ideal range of 70-98%.?4?Combined with the established high-throughput pre-processing method,high-resolution screening database and collection screening method,150 groups of easily dyed food sold in Chengdu were screened and analyzed,and regulatory suggestions were put forward.In the 150 groups of 7 samples,62 groups were found to have synthetic pigments,including 3.7%of the seasoning and spices,6.6%of the fans,6.6%of the meat products,15%of the spicy hot noodles,50%of the candy,75%of the frozen drinks,and the highest detection rate of preserved fruits.At the same time,industrial dyes rhodamine B and acid orange II were found in preserves,meat products and condiments.