Study On The Industrial Dyes In Condiments By Liquid Chromatography And Mass Spectrometry

As the saying goes,"Hunger breeds discontent, food-an as the first", food security is related to people’s health and safety of life, is related to economic development and social harmony. In recent years, basic and acid industrial dyes are frequently found be illegally dded into condiments. At present, the research on the basic and acid dyes in food is not enough; it hasn’t the ability to fast screen and identificate industrial dyes in food in emergency. So it is necessary to establish a set of complete methods to determine the dyes which are illegally added into condiments. It could provide technical support to find the food contaminants in seasoning.The screening and determination methods for10basic dyes (auramine O, astrazon orange G, malachite green, rhodamine B, astrazon orange R, leucomalachite green, butyl rhodamine B, basic red2, rhodamine6G, rhodamine110) and9acid dyes (acid red87, acid yellow36, orange2, azorubin, orange3, acid orange67, tracid brilliant red B, acid yellow A-4R, tracid brilliant red A-B) in condiments were established respectively using liquid chromatography ion trap time-of-flight mass spectrometry (LCMS-IT-TOF) and ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The mainly contributions of this study include the following aspects.(1) A method for the determination of10basic dyes in condiments. Residues were extracted by acetonitrile and defatted by n-hexane. After extraction and defatted, the samples were cleaned up on the weak cation exchange solid phase extraction cartridge. The targeted compounds were separated on an Waters Acquity UPLC BEH C18(100mm×2.1mm,1.7μm) column using5mmol/L ammonium acetate-0.1%formic acid acetonitrile as mobile phase by linear gradient elution, and quantified by the matrix matched external standard method. The result indicate that using the LCMS-IT-TOF and UPLC-MS/MS methods,10basic dyes showed good linearities in the range of1.0～100.0μg/L and high correlation coefficents (r2>0.99).The detction limits were in the range of0.5～0.6μg/kg and the quantitation limits were in the range of1.5～2.0μg/kg. The mean recoveries at three spiked level ranged from67.8%～122.8%by LCMS-IT-TOF method, and ranged from68.4%～123.2%by UPLC-MS/MS method.(2) A method for the determination of9acid dyes in condiments. Residues were extracted by methanol-water (80:20, by volume) and defatted by n-hexane. After extraction and defatted, the samples were cleaned up on the weak anion exchange solid phase extraction cartridge. The targeted compounds were separated on an Shimadu Shim-pack XR-ODS (2.0mm I.D.×100mm,2.2μm) column using methanol-10mmol/L ammonium acetate as mobile phase by linear gradient elution, and quantified by the matrix matched external standard method. The result indicate that using the LCMS-IT-TOF and UPLC-MS/MS methods,9acid dyes showed good linearities in the range of0.0005～8mg/L and high correlation coefficents (r2>0.99).The detction limits were in the range of0.0003～0.06mg/kg and the quantitation limits were in the range of0.001-0.2mg/kg. The mean recoveries at three spiked level ranged from64.8%-96.3%by LCMS-IT-TOF method, and ranged from71.4%-126.9%by UPLC-MS/MS method.(3) The above methods were applied to screen the forbidden industrial dyes in condiments. The positive results were matched and identified by the function of precision mass searching and the mass spectrum library searching or by the multiple mass spectrums with standard substance. To suspicious compounds, according to their multiple mass spectrums, their structure were analysed, it makes the identification and predication results more convinced.(4) A new method for the analysis of10basic dyes and another new method for the determination of9acid dyes in condiments were developed using LCMS-IT-TOF and UPLC-MS/MS. The target compounds were well separated and determined using the optimized methods. The multiple mass spectrums of19industrial dyes were got using LCMS-IT-TOF, and the ACDLabs MS library were established. The process of screening and identification of industrial dyes in condiments were established.In conclusion, the developed methods using LCMS-IT-TOF and UPLC-MS/MS were sensitive, effective and reliable for the quantitative and qualitative analysis of industrial dyes in condiments. The methods were suitable for the screening and identification of industrial dyes in condiments.