Application Of The Quality And Safety Of Dairy Products By UPLC-Q Exactive Orbitrap HRMS

The quality and safety of dairy product could directly affect the development of food industry and the human health.In order to further refine the method system of residues detection in dairy product,this paper based on solid-phase extraction and ultra performance liquid chromatography-tandem UPLC-Q Exactive orbitrap HRMS technology to detect veterinary drug residues,sulbactam and lipid components and illegally added chemicals in dairy product.The main work of this paper was as follows:1.A fast and easy method for the screening and quantification of 62veterinary residues in dairy product by ultra high performance liquid chromatography-quadrupole/electrostatic field orbitrap trap high resolution mass spectrometry was developed.Milk powder samples were redissolved with warm water in a certain proportion,and the milk samples were treated directly.They were extracted and precipitated by acetonitrile solution containing 0.2%formic acid and the Oasis~?PRiME HLB Cartridges were used as a clean-up method for multi-residue veterinary drug analysis.Chromatographic analysis was carried out using a Thermo Hypersll GOLD aQ column with acetonitrile-0.1%formic acid aqueous solution as mobile phase by gradient elution.62 veterinary residues were analyzed by high-resolution mass spectrometry in positive mode and quantified by external standard method.The results showed that high correlation coefficients(>0.9906)of all the anaytes were obtained within their respective linear ranges.By detecting and confirming spiked samples,the limits of detection of the milk and milk powder were 0.5μg/kg and 1μg/kg respectively,and limits of quantitation were 5μg/kg and 10μg/kg respectively.The average recoveries ranged from 60.1%to 139.4%with relative standard deviations from0.9%to 15.9%at three concentration levels.This proposed method verified by the actual sample,is simple,reliable,accurate as well as rapid and can be applied for highthroughput screening and confirmation of multiple veterinary residues in milk.2.A fast,accurate and sensitive method by UPLC-Q-Exactive Orbitrap HRMS Spectrometry for the detection of 11 illegally added phosphodiesterase-5inhibitors and their analogues in goat’s milk was developed.Analytes were homosildenafil,vardenafil,aminotadalafil,nor-acetildenafil,acetildenafil,pseudovardenafil,norneosildenafil,thioaildenafil,tadalafil,sildenafil,hydroxyhomosildenafil.Samples were extracted by acetonitrile and purified by Oasis~?PRiME HLB solid Phase extraction column,then were analyzed through a COSMOSIL Packed Column 5C18-MS-∥(2.0 mm×150 mm,3μm),using the mobile phase of acetonitrile-0.1%formic acid water by gradient elution.The flow rate was 0.2 mL/min and mass data were acquired with the ESI(+)mode and orbitrap was used as detector for qualitative and quantitative analysis.A good linear relationship was showed in the concentration of 0μg/L~50μg/L,and the average spiked recoveries of the method varied from 62.1%to 96.7%,with relative standard deviations(RSDs)between 1.6%and 6.0%.The method is simple,reliable and sensitive for determination of illegally added phosphodiester-ase-5 inhibitors and their analogues in goat’s milk.3.A new method to determine sulbactam in liquid milk samples was developedbasedon new typeSPE-ultrahigh performance liquid chromatography-quadrupole/electrostatic field orbitrap trap high resolution mass spectrometry.Samples were extracted by acetonitrile,and then purified by a new type SPE(Oasis~?PRiME HLB).Chromatographic analysis was carried out using a Thermo Hypersll GOLD aQ,with the optimized mass resolution,accurate mass measurement of analyte was obtained by using full scan mode and two stage threshold triggered full mass scan mode was utilized to further improve the accuracy of qualitative analysis.The linear range of sulbactam was from 0.5μg/L to 10μg/L and the limit of quantification(LOQ)of sulbactam was 0.5μg/kg.The average spiked recoveries of the method varied from 82.1%to 95.5%with relative standard deviations(RSDs)between 3.5%and 6.2%.The method is simple and accurate for determination of sulbactam in liquid milk.