Sin-QuEChERS净化-超高效液相色谱-串联质谱法测定鱼肉中8种喹诺酮类药物残留量

UHPLC-MS/MS Determination of8 Quinolone Drugsin Fish with Sin-QuEChERS Purification

将粉碎后的鱼肉样品2.00 g置于50 mL离心管中,加入100μg·L^(-1)内标溶液200μL和水5 mL,涡旋1 min后,用含5%(体积分数)乙酸的乙腈溶液10 mL超声提取10 min,加盐包(6 g无水硫酸镁、1.5 g氯化钠)使水相和乙腈相进行分层.涡旋、离心后,使用Sin-QuEChERS快速滤过柱直接插入离心管内,待提取液透过净化层上升至净化柱内时,移取5 mL提取液置于15 mL离心管内,加入体积比1∶1的乙腈-正己烷混合液5 mL,混匀静置,取上层正己烷层涡旋,离心,于40℃氮气吹至近干,用0.2%(体积分数)甲酸溶液定容至1 mL,过滤后上机UHPLC-MS/MS,在多反应监测模式下测定8种喹诺酮类药物的残留量.结果显示:该净化方法溶剂消耗降低至10 mL,前处理时间缩短至20~25 min.环丙沙星、培氟沙星、诺氟沙星、二氟沙星和达氟沙星标准曲线的线性范围均为1.00~500.0μg·L^(-1),检出限(3S/N)均为1.0μg·kg^(-1);氧氟沙星、恩诺沙星和沙拉沙星标准曲线的线性范围为0.50~500.0μg·L^(-1),检出限(3S/N)均为0.5μg·kg^(-1).用此法平行测定同一样品7次,测定值的相对标准偏差为1.3%~6.3%.按标准加入法进行回收试验,回收率为92.0%~108%.此法用于抽检兰州4家超市的3种鱼类,8种喹诺酮类药物均未检出,说明兰州市的鱼类食品中的药物残留问题相对安全.同时,与国家农业部1077号公告-1-2008中方法进行比对,测定结果基本一致.

Thecrushedfishsample(2.00 g)was placedina50 mL-centrifugetube,and200μLof100μg·L^(-1)internal standard solution and 5 mL of water were added.After vortex for 1 min,the above mixture was extracted ultrasonicallyfor10 min with 10 mL ofacetonitrilesolutioncontaining 5%(φ)acetic acid,andthe salts(6 g ofanhydrous magnesium sulfate and 1.5 g of sodium chloride)were addedto separatethe aqueous phase and acetonitrile phase.Aftervortexandcentrifugation,Sin-QuEChERSrapidfiltrationcolumn was directlyinsertedinto thecentrifugetube.Whentheextractrosetothe purifyingcolumnthroughthe purifyinglayer,5 mLoftheextract wastransferredintoa15 mL-centrifugetube,a mixtureofacetonitrileandn-hexaneatthevolumeratioof1∶1 was added,and then the mixture was mixed well and settled.The upper n-hexane layer of was taken,then swirl,centrifugedand blownto nearly dryat40℃with nitrogen.The residue was madeits volumeto 1 mL with 0.2%(φ)formic acid solution.Afterfiltration,8 quinolones residues were determined by ultra high performanceliquid chromatographytandem mass spectrometry(UHPLC-MS/MS)under multi-reaction monitoring mode.As shown bytheresults,theconsumption ofthe solvent was reduced to 10 mL and the pretreatmenttime was shortened to 20-25 min by this purification method.The linear ranges of the standard curves of ciprofloxacin,pefloxacin,norfloxacin,difloxacin and danofloxacin were 1.00-500.0μg·L^(-1),with the same detection limits(3S/N)of 1.0μg·kg^(-1).The linear ranges of the standard curves of ofloxacin,enrofloxacin and sarafloxacin were 0.50-500.0μg·L^(-1),withthesame detectionlimits(3S/N)of0.5μg·kg^(-1).Thesamesample was determined7 times in parallel bythis method,with RSDs ofthe determined valuesintherangeof1.3%-6.3%.Testforrecovery was made bystandard addition method,giving results in the range of 92.0%-108%.This method was applied for samplinginspection of 3 kinds of fish from 4 supermarkets in Lanzhou,and 8 quinolones were not detected,showingthatdrugresiduesinfishfoodin Lanzhou wererelativelysafe.Atthesametime,theresults were basically consistent withthose ofthe methodin Proclamation No.1077-1-2008 ofthe State Ministry of Agriculture.