采用有机进样系统-电感耦合等离子体质谱法直接进样测定食用油中铅、砷、铜、铝、镍

目的采用加氧附件-有机进样系统建立了ICP-MS直接进样测定食用油中铅、砷、铜、镍、铝等元素的分析方法。方法采用航空煤油为稀释剂,按照油/溶剂(质量比)1/9加以稀释后直接进入ICP-MS仪器分析,采用钇、铍混合内标来补偿仪器信号漂移和基体效应。结果方法检出限:铅为0.09μg/kg、砷为0.07μg/kg、铜为0.1μg/kg、镍为0.11μg/kg、铝为0.55μg/kg;相对标准偏差5%;加标回收率在95%~105%之间。结论该研究所建立的方法适用于食用油等有机样品中重金属元素的检测分析。     

固相萃取原子荧光光谱法检测稻米和虾仁中的无机硒

建立了氨水提取、三氯乙酸沉淀蛋白、阳离子交换净化分离,原子荧光光谱检测稻米和虾仁中无机硒的新方法。样品经氨水超声提取,三氯乙酸沉淀蛋白,Cleanert PCX小柱分离,HNO_3-HClO_4消解,HCl还原,原子荧光光谱法进行检测。结果显示,无机硒能被有效提取、分离和检测。方法在(0. 1～4. 0μg/L)浓度范围内,R~2 0. 99,仪器检出限(IDL)为0. 040μg/L,方法检出限(MDL)为1. 60μg/kg。稻米和虾仁样品的加标回收率分别为84. 1%～98. 7%和89. 8%～109. 3%,相对标准差分别为2. 3%～10%和2. 2%～3. 1%。对产地不同的稻米和虾仁样品的实际检测显示,稻米无机硒含量分别为3. 88～45. 90μg/kg,占总硒的百分比最高值为11. 27%,虾仁样品无机硒含量为小于MDL～24. 76μg/kg,占总硒的百分比最高值为3. 83%。     

高效液相色谱-发光二极管诱导荧光法快速检测饲料中的苯并[a]芘

基于自行设计与组装的发光二极管(LED)诱导荧光检测器,结合高效液相色谱分离,发展了一种饲料中苯并[a]芘的快速测定方法。样品以乙腈作为提取溶剂,超声提取30min,上清液过滤后直接采用高效液相色谱-LED诱导荧光检测进行分析。结果表明:方法检出限(S/N=3)为0.23μg/kg;阴性饲料样品3个加标水平1.0μg/kg、5.0μg/kg、20.0μg/kg,回收率为81%~105%,相对标准偏差(RSD,n=7)为3.27%~9.67%。与常规检测方法相比,本方法不仅充分发挥了荧光检测法灵敏度高的优势,更重要的是简化了样品前处理,缩短了分析时间、减少了样品处理量和溶剂消耗量。     

全自动固相萃取/高效液相色谱-串联质谱法（HPLC-MS/MS）测定深海鱼中雪卡毒素残留量

建立了深海鱼鱼肉中雪卡毒素残留的高效液相色谱-串联质谱检测方法。虎鳗等样品经甲醇-正己烷(4∶1)提取,HLB柱净化后,采用高效液相色谱-串联质谱分析,外标法定量。质谱分析采用电喷雾电离,正离子扫描,多反应监测模式。定性离子对为m/z 1 128.9/1 057.6、1 128.9/1 039.9、1 128.9/1 075.8。实验结果表明,HLB柱净化后基质效应明显降低,样品中添加0.01～0.1μg/kg的雪卡毒素,其回收率为70%～84%,相对标准偏差(n=6)小于7%;雪卡毒素的检出限为0.01μg/kg,定量下限为0.02μg/kg。该方法样品前处理简单、分析时间短、灵敏、可靠,适用于深海鱼中雪卡毒素含量的检测。     

同位素稀释高效液相色谱-串联质谱法测定面粉及面制品中的联二脲

建立了面粉及其制品中联二脲的同位素稀释高效液相色谱-串联质谱检测方法。采用纯水超声提取,含油脂的样品加正己烷脱脂,所得样液进行高效液相色谱-串联质谱测定。以乙腈与纯水为流动相,梯度洗脱,经Waters XBridge BEH Amide(3.5μm,4.6 mm×150 mm)色谱柱分离,MS/MS采用电喷雾电离正离子(ESI+),多反应监测(MRM)模式检测,同位素内标法定量。方法的线性范围为0.2~100μg/L,相关系数为0.999 9;在面粉、馒头、面包、油条和面条5种基质中的平均加标回收率为82.0%~113.6%,相对标准偏差(RSD)为2.1%~9.3%;方法定量下限(LOQ)为20μg/kg。应用该方法对136份市售的面粉及面制品进行检测,在42份样品中检出联二脲,检出率为30.88%。其中面粉检出4份,含量为43.7~564μg/kg;馒头未检出;面条检出2份,分别为70.8μg/kg与9 840μg/kg;油条检出1份,含量为2 480μg/kg;面包表层检出15份,含量为27.4~8 730μg/kg;面包内芯检出20份,含量为64.3~18 100μg/kg。该方法操作简单、灵敏快速、准确可靠,适用于面粉及其制品中联二脲的测定。     

顶空固相微萃取-气相色谱-质谱法测定茶叶中香叶醇

建立了一种应用顶空固相微萃取(HS-SPME)气相色谱质谱(GC-MS)联用分析测定茶叶中香叶醇(Geraniol)的方法。通过考察萃取头型号、茶水比、萃取温度、萃取时间、解吸附温度和解吸附时间等影响因素,确定最佳HS-SPME条件为:DVB/CAR/PDMS型号萃取头、茶水比1:6、萃取温度60℃、萃取时间60 min;气相色谱最佳解吸附条件为:进样口温度240℃、解吸附时间3 min。在优化条件下茶叶样品中的香叶醇得到较好的提取,GC-MS检测线性范围为0.08~16.50μg/g,检出限(S/N≥3)为9.42×10-3μg/g,空白基质加标回收率为89.8%~105.9%。在对24种茶样进行检测后,香叶醇含量范围为0.13~11.85μg/g,相对标准偏差为1.8%~9.7%。方法能满足茶叶样品中香叶醇分析测定的需要。     

超高效液相色谱-串联质谱法测定食用油中16种真菌毒素

建立超高效液相色谱–串联质谱法测定食用油中黄曲霉毒素、玉米赤霉烯酮、伏马毒素等16种真菌毒素的方法。样品经乙腈–水–甲酸(体积比为80∶19∶1)振荡提取,过六合一真菌毒素免疫亲和柱净化,提取液用Waters ACQUITY UPLC BEH C18 (150 mm×2.1 mm, 1.7μm)色谱柱进行分离,采用内标法定量测定。方法的检出限为0.1～16.5μg/kg,定量限为0.3～50μg/kg,测定结果的相对标准偏差为2.3%～9.2%(n=6),平均回收率为75.9%～104.5%。该方法净化效果好,灵敏度高,具有良好的精密度与准确度,适用于同时检测食用油中的16种真菌毒素。     

超高效液相色谱-串联质谱法同时测定食用油中痕量的δ-9-四氢大麻酚、大麻酚和大麻二酚

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定食用油中δ-9-四氢大麻酚(THC)、大麻酚(CBN)和大麻二酚(CBD)的方法。目标分析物经甲醇提取、中性氧化铝固相萃取柱净化后,采用UPLC-MS/MS分离和检测。实验以氘代四氢大麻酚(THC-D3)为内标物,采用同位素内标法定量。在3个添加水平下,目标物的平均回收率为68.0%～101.6%,相对标准偏差为7.0%～20.1%。方法检出限为0.06～0.17μg/kg,定量限为0.20～0.52μg/kg。该方法能够满足食用油中痕量四氢大麻酚、大麻酚和大麻二酚检测的需要。     

高效液相色谱-串联质谱法测定蔬菜和水果中氟吗啉的残留量

建立了高效液相-串联质谱法(LC-MS/MS)分析蔬菜和水果中氟吗啉残留量检测的方法。通过氟吗啉光照实验,研究了氟吗啉顺反异构体转化规律。以醚菌胺为内标(I.S.),乙酸乙酯提取,经HLB(亲水-疏水净化住)固相萃取小柱净化并富集后,以液相色谱分离,采用质谱正离子多反应监测模式进行定量分析。方法定量限为0.05μg/kg;线性范围为0.05～25μg/kg;提取回收率为77.64%～92.83%;相对标准偏差均小于8.6%。本方法灵敏度高、选择性好,实际样品检测中的检出率达到70%;样品中最高残留量为1.83μg/kg,能满足蔬菜和水果中氟吗啉残留量检测要求。     

高效液相色谱法测定食品中丙二醛

采用高效液相色谱法测定各类食品样品中的丙二醛含量,建立了对猪肉、方便面、食用油、大白菜、婴儿配方奶粉和饼干等不同食品基质均适用的分析方法,采用样品加标的方法验证了方法的可行性。样品采用酸液恒温振荡提取,硫代巴比妥酸衍生提取液后,采用Agilent Eclipse XDB-C18色谱柱进行分离测定,以0.01 mol/L乙酸铵(A)-甲醇(B)(7+3,V/V)为流动相进行色谱等度分离,流速1.0 mL/min,柱温30℃,检测波长532nm。结果表明,丙二醛含量为0.125~2 mg/kg时线性良好,相关系数不小于0.9997。在0.1,1.0和2.5 mg/kg 3个添加水平下的回收率为61%~98%,日内精密度(相对标准偏差,RSD)小于8.3%,日间精密度小于9.2%,检测限为7.72μg/kg,方法稳定性良好。     

离子色谱法测定“地沟油”中钠离子和氯离子的含量及其比例关系

采用离子色谱法测定“地沟油”样品中钠离子和氯离子的含量,通过计算两者的比例关系确定样品中是否含有“地沟油”。使用去离子水提取“地沟油”样品中钠离子和氯离子。氯离子以20 nmol/L KOH溶液为淋洗液,AS19分离柱(250 mm×4 mm)分离,抑制器电流112 mA;钠离子以20 nmol/L甲基磺酸(MSA)为淋洗液,CS12分离柱(250 mm×4 mm)分离,抑制器电流59 mA;两者分离采用的其他相同色谱条件为: 柱温、检测器温度30 ℃,电导检测器检测,进样量25 μL,流量1 mL/min,峰面积定量。氯离子的检出限为0.005 mg/L,在0～5 mg/L范围内有良好的线性关系（r2=0.999988）;钠离子的检出限为0.001 mg/L,在0～5 mg/L范围内有良好的线性关系（r2=0.999926）。氯离子平均加标回收率为94.2%,相对标准偏差(RSD)为2.4%;钠离子平均加标回收率为92.5%, RSD为2.7%。经测定、计算,正常食用油中钠离子和氯离子的物质的量比约为1,而“地沟油”中钠离子与氯离子的物质的量比高于4。“地沟油”中钠离子和氯离子的含量及其比例关系可作为判断“地沟油”的重要依据。     

Determination of triazole pesticide residues in edible oils using air‐assisted liquid–liquid microextraction followed by gas chromatography with flame ionization detection

In the present study, a rapid, simple, and highly efficient sample preparation method based on air‐assisted liquid–liquid microextraction followed by gas chromatography with flame ionization detection was developed for the extraction, preconcentration, and determination of five triazole pesticides (penconazole, hexaconazole, diniconazole, tebuconazole, and triticonazole) in edible oils. Initially, the oil samples were diluted with hexane and a few microliter of a less soluble organic solvent (extraction solvent) in hexane was added. To form fine and dispersed extraction solvent droplets, the mixture of oil sample solution and extraction solvent is repeatedly aspirated and dispersed with a syringe. Under the optimum extraction conditions, the method showed low limits of detection and quantification between 2.2–6.1 and 7.3–20 μg/L, respectively. Enrichment factors and extraction recoveries were in the ranges of 71–96 and 71–96%, respectively. The relative standard deviations for the extraction of 100 and 250 μg/L of each pesticide were less than 5% for intraday (n = 6) and interday (n = 3) precisions. Finally edible oil samples were successfully analyzed using the proposed method, and hexaconazole was found in grape seed oil.     

大气压化学电离-高分辨质谱直接分析食用油中的甘油三酯

建立了食用油中甘油三酯的大气压化学电离-质谱直接分析检测方法.在考察实验条件影响的基础上,选择乙腈作为溶剂,正离子检测模式,进样流速为800 μL/h,喷雾器温度250℃,电晕针电流为5000 nA.用本方法对10种食用油进行分析,结果表明,植物油与动物油之间差异较大.经主成分分析,选择m/z 857.76与m/z 881.76峰强度比作为指标,重复性RSD＜5％,可直接识别出玉米油中掺杂5％的猪油.用碰撞诱导解离(CID)实验初步鉴别了食用油的3个特征峰.利用本方法对泔水油样品和煎炸油样品进行分析,结果泔水油样品中含有植物油和动物油,而煎炸油样品也与商品食用油存在差异.本方法可用于食用油样品的快速筛查.     

固相萃取/高效液相色谱法测定茶油中的多种天然酚类物质

建立了同时分离、检测茶油中23种酚类物质的高效液相色谱方法.比较了液液萃取、固相萃取两种方法的提取效果,并优化了流动相、检测波长、进样量等参数.23种酚类物质在优化条件下均可有效分离,并在0.059～9.115μg/g范围内具有良好的线性关系,相关系数为0.9776～1.0000,检出限为0.041～0.379μg/g...     

采用新型固相萃取柱快速测定食用植物油中苯并［a］芘

研究了Bond Elut ENV新型固相萃取柱在食用植物油中苯并[a]芘快速检测中的应用,建立了快速测定食用植物油样品中苯并[a]芘残留量的固相萃取/液相色谱/荧光检测法。样品用正己烷溶解,固相萃取净化,SUPELCOSILTMLC-PAH(25 cm×4.6 mm,5μm)色谱柱分离,以乙腈-水(95∶5)为流动相,荧光检测(λex=297 nm,λem=408 nm),外标法定量。苯并[a]芘的检出限为0.3μg/kg,在1.0～50.0μg/L范围内线性关系良好,相关系数为0.999 6,方法的回收率为79%～102%,相对标准偏差不高于9.4%。该方法准确、实用、简便、快速,在食用植物油的苯并[a]芘残留量检测方面有广泛的应用前景。     

Low temperature purification method for the determination of abamectin and ivermectin in edible oils by liquid chromatographytandem mass spectrometry

In this study,a method based on low temperature purification(LTP) coupled with liquid chromatography-tandem mass spectrometry(LC-MS/MS) was developed for the determination of abamectin(ABA) and ivermectin(IVR) in edible oils.ABA and IVR were extracted using conventional liquid-liquid extraction followed by purification via precipitation of interfering fatty components at low temperature without an additional cleanup step.LTP is simple,easy to use,labour-saving and cost effective,and requires reduced amounts of organic solvent.The linear ranges of ABA and IVR were 5-1000 μg/L using matrix-matched standards.Limits of detection(LOD) and limits of quantification(LOQ)were in the range of 0.1-0.4 μg/kg and 0.3-1.3 μg/kg,respectively.The LOQs were below the strictest maximum residue limits established by Codex Alimentarius Commission.Recoveries at three spiked levels of 10,20 and 100 μg/kg in peanut oil,corn oil,olive oil,soybean oil and lard ranged from 71.1%to119.3%with relative standard deviations of 3.2%-10.3%,which were in agreement with those obtained by the solid phase extraction method.The proposed method was utilized in the analysis of 10 edible oil samples from local market and neither ABA nor IVR was detected.As far as we know,this is the first time that LTP is applied to the determination of avermectins in edible oils.     

Fast and effective low‐temperature freezing extraction technique to determine organotin compounds in edible vegetable oil

Most organotin compounds that have been widely used in food packaging materials and production process show serious toxicity effects to human health. In this study, a simple and low‐cost method based on high‐performance liquid chromatography with inductively coupled plasma mass spectrometry for the simultaneous determination of four organotins in edible vegetable oil samples was developed. Four organotins including dibutyltin dichloride, tributyltin chloride, diphenyltin dichloride, and triphenyltin chloride were simultaneously extracted with methanol using the low‐temperature precipitation process. After being concentrated, the extracts were purified by matrix solid‐phase dispersion using graphitized carbon black. The experimental parameters such as extraction solvent and clean‐up material were optimized. To evaluate the accuracy of the new method, the recoveries were investigated. In addition, a liquid chromatography with tandem mass spectrometry method was also proposed for comparison. The procedures of extracting and purifying samples for the analysis were simple and easy to perform batch operations, also showed good efficiency with lower relative standard deviation. The limits of detection of the four organotins were 0.28–0.59 μg/L, and the limits of quantification of the four organotins were 0.93–1.8 μg/L, respectively. The proposed method was successfully applied to the simultaneous analysis of the four organotins in edible vegetable oil. Some analytes were detected at the level of 2.5–28.8 μg/kg.     

Optimization of ultrasonic-assisted extraction of 3-monochloropropane-1,2-diol (MCPD) and analysis of its esters from edible oils by gas chromatography-mass spectrometry

In this paper, ultrasonic-assisted extraction of 3-chloropropane-1,2-diol and its esters from edible oils was studied with isotope dilution GC-MS. Effects of several experimental parameters, such as types and concentrations of extracting solvent, ratios of liquid to material, extraction temperature, time of ultrasonic treatment on the extraction efficiency of 3-chloropropane-1,2-diol and its esters from edible oils and sample preparation for calibration were compared and optimized. The optimal extraction conditions were suggested as 66 mg oil sample in mixture of 0.5 mL MTBE/ethyl acetate (20% v/v) and 0.5 mL of sulfuric acid/n-propanol (0.3% v/v), being extracted for 30 min at 45°C under ultrasonic irradiation. Good linearity was gained in the range of 0.020-5.000 μg/g with the limit of detection (LOD) of 0.006 μg/g (S/N = 3) and the limit of quantification (LOQ) of 0.020 μg/g (S/N = 10). The recoveries at five spiked concentrations were ranged from 91.9 to 109.3% with RSD less than 9.4%. The method was successfully applied to the determination of 3-chloropropane-1,2-diol and its esters amounts in rapeseed, sesame, peanut, camellia, and soybean oils.     

高效液相色谱法测定淀粉及淀粉制品中的顺丁烯二酸与顺丁烯二酸酐总含量

建立了基于高效液相色谱(HPLC)测定淀粉及其制品中顺丁烯二酸和顺丁烯二酸酐总含量的方法。通过优化得到最佳样品前处理条件为乙醇体积分数5%,超声时间10 min。色谱分离检测的最佳分析条件为:流动相:甲醇-1‰磷酸(2∶98),色谱柱:Plastisil ODS C18(250 mm×4.6 mm,5μm),检测波长214 nm,流速1.0 mL/min,柱温30℃。该方法对顺丁烯二酸的定量下限为5.0 mg/kg,线性范围为0.25～100 mg/L,相关系数为0.999 7,平均加标回收率为88%～89%,相对标准偏差(n=5)小于2%,能够满足实际检测需要。     

微波萃取气相色谱法测定淀粉中14种有机氯农药残留

建立了淀粉中14种有机氯农药:六六六及滴滴涕的4种异构体、五氯硝基苯、四氯硝基苯、四氯苯胺、五氯苯胺、腐霉利、甲基五氯苯基硫醚(MPCPS)的微波辅助和气相色谱分析方法.优化了气相色谱检测条件,考察了提取方法、萃取条件、净化条件对提取效果的影响.目标农药在20～200 μg/kg范围内线性良好,平均回收率在68%～10...