| Poultry farming industry is most important in our country with a large population.The huge demand for meat consumption also contributed to the growing demand forveterinary drugs with the continuous improvement of living standards. The excessiveuse of veterinary medicine, especially antibiotics, leads in serious pollution problems.Thus, the existence of veterinary drug residues from all sources in meal has becomea serious threat to human health. Considering food safety is a serious livelihood,therefore, it is necessary to detect animal veterinary drug residues in food.The presence and harm of veterinary drugs residues and metabolites are relative tothe nature of veterinary medicine, but also on the environment. Veterinary drugresidue analysis is a complex process, including sample pre-treat and detect. Theformer is especially critical, which includes extraction, purification, concentrationand so on. It takes time about60%of the entire analysis process to pre-treat sample,which requires not only extract the analytes, also remove impurities as possible, sothat reduce interference on the results and avoid column and detector contamination,etc. In this work, a simple and effective extraction method based on matrix solidphase dispersion (MSPD) and Ultra-fast liquid chromatography (UFLC) wasdeveloped for determination of veterinary drugs from beef and the Sudan dyes(SudanⅠ, SudanⅡ,SudanⅢ, SudanⅣ) from Hawthorn tablets. A method based onmatrix solid phase dispersion (MSPD) and GC-MS was developed for determination of flavoring components of white spirit. We separated and detected sulfa veterinarydrug residues in beef and Sudan residual in hawthorn tablets. This method is a rapidand high separation performance.Sulfa drugs (Sulfonamides, SAs) are a class drug of amino benzene sulfonamide. Acombined MSPD and UFLC was applied for the simultaneous determination ofsulfonamides veterinary drugs residues in beef tissue, including sulfathiazole (ST),sulfamerazine (SM1), sulfamethoxazole (SMZ) and sulfadimethoxypyrimidine(SDM). Experimental conditions for the chromatographic mobile phase wereinvestigated, the results showed that acetonitrile-water (30:70, V/V) as the mobilephase, flow rate:0.4mL/min, injection volume of5μL, column temperature was40℃, isocratic elution, detection wavelength:270nm, separated time15min.While the extraction experimental condition of MSPD were also studied, includingdispersants, eluent, sample and dispersant mass ratio and other conditions. Theoptimum conditions are: diatomite as dispersant,6mL of methanol as eluent, ssample-dispersing agent (1:4, m/m). In the report,0.2g of beef and a certainamount of dispersant was added into sulfa standard solution in turn and grinded touniform. A layer of absorbent cotton and0.5g of dispersant as a purification layerwere put on the bottom of a10mL syringe. And then transfer the mixture to thesyringe. Subsequently, a layer of absorbent cotton was placed at the top of andcompaction. The target analytes was eluted, collected, dried with N2, and redispersedin100μL of acetonitrile. The analytes were filtered through a0.22μm pore sizemembranes. The sample count is5μL into the ultra-fast liquid chromatography(UFLC) for analysis. The detection limit was4.39–7.82μg/kg, quantification limitwas14.62–26.08μg/kg. The recovery for4sulfonamide compounds were71.73%–113.13%, RSDs were1.9%to12.7%. The results are less than the EUstandard (single sulfa drugs≤25μg/kg, the total amount of sulfa drugs≤100μg/kg), and our country standard (MRLsulfa drugs in animal tissues is100μg/kg).Based on complex food matrix and level quantity Sudan illegally added in food, theMSPD was chosen to eliminate the interference so that detect the trace Sudan in thecomplex food matrices. In this work, a combined MSPD and UFLC method was applied to detect the Sudan dye from Hawthorn tablets. Experimental conditionswere investigated, the results showed that acetonitrile-water as the mobile phase,flow rate:0.3mL/min, injection volume of10μL, column temperature was30℃,gradient elution:0–1.0min,5%B;1–7.5min,5%–8%B;7.5–8.0min,8%–3%B;8.0–15.0min,3%B;15.0–16.0min,3%–5%B, detection wavelength:520nm(Sudan I),478nm (Sudan II, III and IV). The optimum conditions for MSPD are:0.45g silicone as dispersant,6mL of ethyl acetate as eluent, sample-dispersant agent(1:3m/m). In the report,0.15g sample and0.45g silicone were mixed and grindedto uniform. A layer of absorbent cotton and0.5g of dispersant as a purification layerwere put on the bottom of a10mL syringe. And then transfer the mixture to thesyringe. Subsequently, a layer of absorbent cotton was placed at the top of andcompaction. The target analytes was eluted by6mL ethyl acetate, collected, driedwith N2below40oC, and redispersed in200μL of acetonitrile. The analytes werefiltered through a0.22μm pore size membranes. Finally, the sample was analyzed byUFLC. Under these conditions, Sudan I–IV recoveries were between86.1%and108.3%; RSDs was2.3%to9.8%. The linear range was0.01–2.5mg/kg (Sudan I, IIand III),0.025–2.5mg/kg (Sudan IV) and the detection limit was4.2–8.9μg/kg. Theresults is better than the National Standards of China detection limit (detection limitis: Sudan I0.017mg/L, Sudan II0.020mg/L, Sudan III0.025mg/L, Sudan IV0.037mg/L) and match with the real sample analysis.The flavoring components of white spirit are complex and the volatile componentsare rich and varied. Because the gas chromatography has congenital advantage forthe detection of volatile components and there are mass spectrometry standardlibrary, the recognition and identify of materials become easy. In this study, a methodwas developed to get more volatile components and capture a larger proportion ofvolatile components.5mg HLB column filling was taken as dispersing agent and the3mL methanol was taken as eluent for pretreatment of samples. The injectortemperature of mass spectrometer was250℃. The starting temperature of columntemperature box was60℃and temperature programmed. Helium was carried gasand the flow rate was set at1mL/min. The results showed that more than20kinds of volatile components were detected such as pentanoic acid, acetic acid, phenethylalcohol, enanthylic acid, octoic acid, nonanoic acid, sixteen acid ethyl ester, and soon. There are7kinds of acid,9kinds of ester and2kinds of alcohol. When5mgLC-CN column filling was selected as dispersing agent, more than10kinds ofvolatile components were detected such as ethyl caproate, ethyl oenanthate, hexanoicacid, palmitic acid methyl ester, methyl stearate,13-stearic acid methyl ester,9,12-eighteen octadecadienoic methyl ester, and so on. There are3kinds of acid,12kinds of ester. The volatile substances was85.88%of all components using thismethod. Especially, it has a good effect on the extraction and enrichment of13-stearic acid methyl ester and the relative content could reach44.94%. |
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