免疫亲和柱净化-高效液相色谱法同时检测鸡蛋中6种玉米赤霉醇类化合物残留量

建立了鸡蛋中6种玉米赤霉醇类化合物(α-玉米赤霉醇、β-玉米赤霉醇、α-玉米赤霉烯醇、β-玉米赤霉烯醇、玉米赤霉酮和玉米赤霉烯酮)残留量的免疫亲和柱净化-高效液相色谱检测方法。样品酶解后用叔丁基甲醚提取、氢氧化钠反萃取,经免疫亲和柱富集和净化后,采用高效液相色谱-紫外检测器进行测定。色谱柱: Agilent Eclipse XDB-C18(150 mm×4.6 mm, 3.5 μm);流动相: 甲醇-乙腈-水(50:15:35, v/v/v);流速: 1.0 mL/min;检测波长: 270 nm。结果表明,6种目标物在0.01～0.2 mg/L范围内线性关系良好,相关系数(r)≥0.9998,检出限(LOD,S/N≥3)为1.0 μg/kg,平均回收率为73.2%～95.7%,相对标准偏差小于8%。该方法灵敏度高、重现性好,适用于鸡蛋样品中痕量玉米赤霉醇类药物残留的测定。     

快速高分离液相色谱-串联质谱法测定植物组织中雌激素玉米赤霉醇类化合物

应用快速高分离液相色谱-串联质谱仪(RRLC-MS/MS),建立了植物组织中玉米赤霉醇类化合物(α-玉米赤霉醇、β-玉米赤霉醇、α-玉米赤霉烯醇、β-玉米赤霉烯醇、玉米赤霉酮、玉米赤霉烯酮)的检测方法.植物组织样品采用乙腈提取,碱性水溶液反萃取,经混合阴离子(MAX)固相萃取柱进行净化和富集后,用RRLC-MS/MS检测,多反应监测(MRM)模式下进行定性与定量分析.结果表明:玉米赤霉醇类化合物在0～20 μg/kg的线性范围内均具有良好的线性关系,方法检出限(LOD)为0.5 μg/kg,定量限(LOQ)为1.0 μg/kg,6种玉米赤霉醇类化合物的平均回收率为75.8%～105.4%,相对标准偏差为2.4%～12.1%.本方法可用于植物组织中玉米赤霉醇类化合物含量的测定.     

高效液相色谱–串联质谱内标法测定动物源性食品中玉米赤霉烯酮及其代谢产物

建立高效液相色谱–串联质谱法(HPLC–MS/MS)测定动物源性食品中玉米赤霉烯酮及其5种代谢产物(α-玉米赤霉烯醇、β-玉米赤霉烯醇、α-玉米赤霉醇、β-玉米赤霉醇、玉米赤霉酮)残留量。在样品中加入4种同位素内标(13C18–玉米赤霉烯酮,D7–α-玉米赤霉烯醇,D7–β-玉米赤霉烯醇,D5–α-玉米赤霉醇)后,经β-葡萄糖苷酶/硫酸酯酶酶解,用叔丁基甲基醚萃取,取上清液氮吹至近干后用三氯甲烷复溶,再用氢氧化钠溶液反向萃取,以HLB固相萃取柱净化后,用HPLC–MS/MS检测。结果表明,玉米赤霉烯酮及其代谢产物在1.0~100.0μg/L范围内线性关系良好,相关系数均大于0.996,方法的检出限为0.04~0.13μg/kg,定量限为0.11~0.43μg/kg。在1.0、4.0、10.0μg/kg三种加标浓度水平下,回收率为77.7%~105.5%,测定结果的相对标准偏差为4.8%~9.8%(n=6)。该方法准确、可靠,灵敏度高,适用于动物源性食品中玉米赤霉烯酮及其代谢产物的定量分析。     

电化学柱后衍生-高效液相色谱法同时测定婴幼儿辅食中4种黄曲霉毒素

建立了同时测定婴幼儿辅食中的黄曲霉毒素B1、B2、G1和G2(AFB1、AFB2、AFG、AFG2)的电化学柱后衍生-高效液相色谱法。样品经丙酮-水(4∶1,V/V)提取后,通过免疫亲和柱富集净化,采用Intersil ODS-SP C18柱,以1.0 mmol/L KBr溶液和40%甲醇-乙腈(1∶1,V/V)溶液为流动相,电化学柱后衍生,荧光检测器检测。AFB1、AFB2、AFG1、AFG2分别在0.4905~9.810、0.1445~2.890、0.4899~9.798和0.1566~3.131ng/mL范围内有良好的线性关系,相关系数R分别为0.9995、0.9999、0.9998和0.9999,检出限(S/N=3)分别为0.05、0.02、0.04、0.02μg/kg。对空白纯米粉进行3个浓度的加标实验,其回收率在91.2%~115.2%之间。该方法重现性好,灵敏度高,定量准确,可应用于婴幼儿不同辅食中以上4种黄曲霉毒素的同时检测。     

免疫亲和柱净化-液相色谱-串联质谱法同时测定猪肉中6种玉米赤霉醇类化合物残留量

建立了猪肉中6种玉米赤霉醇类化合物残留量的免疫亲和柱净化-液相色谱-串联质谱(IAC-LC-MS/MS)分析方法。酶解后的样品用乙醚提取,提取液浓缩后用三氯甲烷溶解,NaOH溶液反萃取,经免疫亲和柱富集和净化后,采用LC-MS/MS进行测定,外标法定量。在Shimadzu Shim-pack VP-ODS C18反相柱上分离,梯度洗脱,流动相为乙腈和2 mmol/L乙酸铵溶液;质谱采集为电喷雾负离子多反应监测模式。6种目标物的线性范围为0.5～200μg/L,相关系数(R)大于0.999,定量限(LOQ)在0.05～0.63μg/kg之间;添加浓度在1.0～5.0μg/kg范围内,方法回收率为71.3%～93.7%,相对标准偏差在3.7%～9.7%之间。该方法灵敏度高、重现性好,适用于猪肉样品中痕量玉米赤霉醇类药物残留的测定。     

高效液相色谱-质谱法同时测定曲霉菌代谢物中的黄曲霉毒素及其同系物

建立了同时检测曲霉菌代谢物中黄曲霉毒素和同系物的超高效液相色谱-线性离子阱质谱测定方法。寄生曲霉(菌株3.124)经PDA液体培养基培养,Qu ECh ERS方法提取净化后经线性离子阱(QTrap)质量分析器分析(正离子模式,多反应检测),检出3.124代谢物中黄曲霉毒素B1(AFB1)、黄曲霉毒素B2(AFB2)、黄曲霉毒素G1(AFG1)、黄曲霉毒素G2(AFG2)、O-甲基杂色曲霉素(MST)、杂色曲霉素(ST)6种真菌毒素。结果表明,6种代谢物在0.1~40μg/L范围内线型关系良好,相关系数均大于0.993,检出限在0.03~0.2μg/L之间,定量限在0.1~0.5μg/L之间。本方法 6种代谢物日内回收率为81.3%~92.1%,相对偏差(RSD)为4.3%~8.6%;日间回收率为81.8%~91.5%,RSD为4.0%~8.7%。方法可满足霉菌代谢物中黄曲霉毒素及其类似物的检测与确证的需要。     

多功能柱净化-柱后光化学衍生-高效液相色谱法同时检测玉米和花生中9种真菌毒素

建立了同时检测玉米和花生中黄曲霉毒素B1、B2、G1、G2、M1、M2、玉米赤霉烯酮、呕吐毒素和展青霉素的多功能柱净化-柱后光化学衍生-高效液相色谱检测方法。样品经乙腈-水(体积比为86∶14)提取,多功能净化柱净化,采用C18柱分离,以甲醇、乙腈和水为流动相进行梯度洗脱,在线光化学衍生,以荧光和二极管阵列测器同时检测。黄曲霉毒素B1、B2、G1、G2、M1、M2、玉米赤霉烯酮、呕吐毒素和展青霉素的检出限分别为0.02μg/kg、0.01μg/kg、0.03μg/kg、0.05μg/kg、0.08μg/kg、0.04μg/kg、0.09μg/kg、0.20mg/kg和0.04 mg/kg,在相应浓度范围内线性相关系数均大于0.999,平均加标回收率为80.0%~101.5%,相对标准偏差在1.3%~5.6%之间。该方法简便快速、灵敏度高、重现性好,可满足玉米、花生中9种黄曲霉毒素的检测。     

在线固相萃取/高效液相色谱-四极杆/静电场轨道阱高分辨质谱检测饲料中的黄曲霉毒素

建立了在线固相萃取/高效液相色谱-四极杆/静电场轨道阱高分辨质谱测定饲料中黄曲霉毒素B1(AFB1)、黄曲霉毒素B2(AFB2)、黄曲霉毒素G1(AFG1)及黄曲霉毒素G2(AFG2)的方法。采用IMMUNOPREPONLINE AFLATOXIN(Part Code:P900)柱为在线固相萃取柱,Diamonsil Plus C18(150 mm×4.6 mm,5μm)柱为分析柱。样品中加入一定量的Na Cl和乙腈-水(80∶20,体积比)溶解,超声提取后,用于后续进样。样品溶液注入在线固相萃取小柱中,通过阀切换技术和HPD共聚焦洗脱模式将保留在SPE柱上的靶标物转移到分析柱中继续进行分离分析,采用外标法定量,采用正离子全扫描模式进行分析。在优化的色谱-质谱条件下,该方法对4种黄曲霉毒素的线性范围为0.5~50.0μg/L,检出限可达0.2μg/kg,定量下限可达0.5μg/kg。在0.5、1.0、5.0μg/kg 3个加标水平下,饲料中4种黄曲霉毒素的回收率为94.6%~114.3%,相对标准偏差不大于8.3%。该方法分析时间短、自动化程度高、检测通量大、检测成本低,可作为饲料中AFB1、AFB2、AFG1、AFG2的快速检测方法。     

Qu ECh ERS/LC-MS/MS法测定食品中7种真菌毒素

建立了食品中常见的黄曲霉毒素B1(AFB1)、黄曲霉毒素B2(AFB2)、黄曲霉毒素G1(AFG1)、黄曲霉毒素G2(AFG2)、赭曲霉毒素A(OTA)、赭曲霉毒素B(OTB)和赭曲霉毒素C(OTC) 7种真菌毒素的QuEChERS前处理净化结合液相色谱-串联质谱(LC-MS/MS)检测方法。样品用甲酸-乙腈(10∶90)进行酸化稀释,离心后取上清液经吸附净化剂(1. 2 g MgSO4+0. 25 g C18+0. 4 g PSA+0. 25 g Al-N)富集净化,过滤后采用LC-MS/MS在多反应监测(MRM)模式下测定。7种真菌毒素在各自范围内线性良好,相关系数(r)均不小于0. 999。在最佳条件下,方法的定量下限(LOQ)为0. 25~5. 0μg/kg,7种毒素的相对标准偏差(RSD,n=6)为1. 1%~7. 7%,平均回收率为71. 5%~119%。该方法操作方便、灵敏度高、重现性好,能满足大批量食品中上述7种真菌毒素残留的检测要求。     

固相萃取-超高效液相色谱-串联质谱法检测粮食及其制品中的玉米赤霉烯酮类真菌毒素

建立了粮食及其制品中6种玉米赤霉烯酮类物质(α-玉米赤霉醇、β-玉米赤霉醇、α-玉米赤霉烯醇、β-玉米赤霉烯醇、玉米赤霉酮和玉米赤霉烯酮)的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法。样品用84%(体积分数)乙腈水溶液提取,通过ENVI-Carb石墨化炭黑(GCB)固相萃取柱进行富集净化,用6 mL二氯甲烷-甲醇(7:3, v/v)溶液洗脱,采用UPLC-MS/MS进行测定。在ACQUITY UPLCTM BEH C18反相柱上分离,梯度洗脱,流动相为水和乙腈;质谱采集模式为电喷雾负离子多反应监测模式。以α-玉米赤霉烯酮-d4为内标,6种目标物的线性范围为0.1～50 μg/L,相关系数(R2)大于0.99,检出限为0.1～0.2 μg/kg, 3个不同水平的加标平均回收率为79.9%～104.0%,相对标准偏差不大于10%。应用该方法对北京市的粮食及相关产品进行了分析,结果发现玉米赤霉烯酮的检出率最高,含量为0.42～220.7 μg/kg;此外还检出了α-和β-玉米赤霉烯醇。该方法具有操作简单、灵敏度高、重现性好等特点,符合食品样品中痕量污染物的检测要求。     

全自动免疫亲和在线净化/高效液相色谱法快速高通量测定饲料中黄曲霉毒素

建立了全自动免疫亲和在线净化/高效液相色谱快速高通量测定饲料中黄曲霉毒素(Aflatoxins,AFT)的分析方法。饲料样品经乙腈-水(80∶20,体积比)提取,3 g/L Triton X-100水溶液10倍稀释后,用自动进样器注入RIDACREST在线固相萃取系统并流经黄曲霉毒素免疫亲和小柱,以甲醇-水(45∶55,体积比)为流动相,流速为1.0 m L/min,C18色谱柱(150 mm×3.5 mm,5μm)分离,光化学衍生,荧光检测器测定。根据3倍信噪比的峰响应值,确定黄曲霉毒素B1,B2,G1,G2的检出限分别为0.08,0.05,0.18,0.08μg/kg,分别在1~100,0.24~24,0.56~56,0.24~24μg/kg范围内呈线性相关,相关系数(r2)分别为0.999 4,0.999 7,0.999 8和0.999 8;AFT在猪饲料、鸡饲料、宠物饲料和饲料原料4类样品中的加标回收率为72.6%~103%,相对标准偏差为2.5%~4.9%。该方法一次装柱可检测60个样品,液相色谱分析一个样品总的运行时间为15 min,所以1 d可检测70~80个样品,满足饲料中黄曲霉毒素快速高通量准确定量检测的需要。     

液相色谱-三重串联四极杆质谱测定粮油中的黄曲霉毒素

建立了超声提取-液相色谱-电喷雾三重串联四极杆质谱测定玉米、大米、大豆等粮油固体样品中黄曲霉毒素B1、B2、G1和G2(AFB1、AFB2、AFG1和AFG2)的方法。分析前对样品进行超声提取,优化得到最佳超声提取条件: 溶剂为甲醇-水(含40 g/L NaCl) (80:20, v/v)溶液、料液比为1:3(g:mL)、温度为50 ℃、时间为3 min。然后对提取的样品进行免疫亲和特异性净化。最后与液相色谱-电喷雾三重串联四极杆质谱联用,使用C18反相色谱柱,流动相为甲醇-10 mmol/L乙酸铵水溶液梯度洗脱,以黄曲霉毒素M1(AFM1)作为内标进行定量测定。结果表明,AFB1、AFB2、AFG1和AFG2的检出限分别为0.002、0.004、0.004和0.012 μg/kg。方法的加标回收率为87%～111%,日内相对标准偏差(RSD)和日间RSD分别不大于6.7%和5.6%。实验结果表明该方法可以有效地降低基质效应的影响,相比于外标法能极大地提高方法的准确度。     

Extraction of aflatoxins B1 and G1 from maize by using aqueous sodium dodecyl sulfate

Aflatoxins are potent carcinogens produced by certain Aspergillus fungi. The aflatoxins were first discovered in the 1960s, and since then have been found to be distributed worldwide in a variety of commodities, foods, and feeds. Many of the early techniques for detecting aflatoxins involved extraction with halogenated solvents. With the increased availability and use of reversed-phase solid-phase extraction cartridges and the availability of immunoaffinity columns, aqueous mixtures of nonhalogenated solvents have been frequently used. To further reduce the need for solvents, we examined the effects of eliminating solvents during the extraction of maize, using aqueous mixtures of the detergent sodium dodecyl sulfate. After extraction and filtration, aflatoxins B1 (AFB1) and G1 (AFG1) were isolated by using commercially available immunoaffinity columns. The isolated AFB1 and AFG1 were derivatized with trifluoroacetic acid before separation by liquid chromatography with fluorescence detection. In spiked maize, the limits of detection were 0.5 and 1 ng/g for AFB1 and AFG1, respectively. Recoveries of AFB1 from maize spiked at 1-20 ng/g averaged 87.5% (range, 76.3-99.0%), with an average repeatability relative standard deviation (RSDr) of 4.0%. Recoveries of AFG1 from maize spiked at 2-20 ng/g averaged 80.4% (range, 70.3-85.8%), with an average RSDr of 3.5%. This is the first reported demonstration of an effective solvent-free extraction of aflatoxins from maize at ambient pressure, and this extraction procedure may serve to help reduce solvent consumption during aflatoxin analysis.     

Use of multitoxin immunoaffinity columns for determination of aflatoxins and ochratoxin A in ginseng and ginger

Conditions were optimized for the simultaneous, alkaline, aqueous methanol extraction of aflatoxins (AFL), i.e., B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2), and ochratoxin A (OTA) with subsequent purification, isolation, and determination of the toxins in ginseng and ginger. Powdered roots were extracted with methanol-0.5% NaHCO3 solution (7 + 3). After shaking and centrifugation, the supernatant was diluted with 100 mM phosphate buffer containing 1% Tween 20 and filtered through glass microfiber filter paper. The filtrate was then passed through an immunoaffinity column, and the toxins were eluted with methanol. The AFL were separated and determined by reversed-phase liquid chromatography (RPLC) with fluorescence detection after postcolumn UV photochemical derivatization. OTA was separated and determined by RPLC with fluorescence detection. Recoveries of AFL added at 2-16 ng/g and OTA added at 1-8 ng/g to ginseng were 72-80 and 86-95%, respectively. Recoveries of AFL and OTA added to ginger were similar to those for ginseng. A total of 39 commercially available ginger products from 6 manufacturers were analyzed. Twenty-six samples were found to be contaminated with AFL at 1-31 ng/g and 29 samples, with OTA at 1-10 ng/g. Ten samples contained no AFL or OTA. Ten ginseng finished products were also analyzed; 3 contained AFL at 0.1 ng/g and 4 contained OTA at levels ranging from 0.4 to 1.8 ng/g. LC/tandem mass spectrometry with multiple-reaction monitoring of 3 collisionally induced product ions from the protonated molecular ions of OTA, AFB1, and AFG1 was used to confirm the identities of the toxins in extracts of the finished products.     

复合免疫亲和柱净化-液相色谱-串联质谱法同时测定动物源性食品中6种玉米赤霉醇类化合物和氯霉素残留量

建立了动物源性食品中6种玉米赤霉醇类化合物和氯霉素残留量的复合免疫亲和柱净化、液相色谱-串联质谱（LC-MS/MS）分析方法。样品（鱼肉、肝脏、牛奶、蜂蜜）经β-葡萄糖苷酸/硫酯酸复合酶酶解后用乙醚提取,提取液经氮气吹干,残渣用50%乙腈溶液复溶后过滤,滤液用PBS溶液稀释,经复合免疫亲和柱富集净化后供LC-MS/MS检测,采用多反应监测（MRM）模式进行定量和定性分析,外标法定量。结果表明,7种目标物的检出限（S/N=3）在0.04~0.10 μg/kg之间,线性相关系数（R²）≥0.9990,平均回收率为70.9%~95.6%,相对标准偏差为2.0%~11.8%。该方法灵敏度高、重现性好,适用于动物源性食品中痕量玉米赤霉醇类药物和氯霉素残留的测定。     

Development and evaluation of analytical methodology for the determination of aflatoxins in palm kernels.

A rapid, simple and reproducible method for the simultaneous estimation of aflatoxins AFB1, AFB2, AFG1 and AFG2 in palm kernel samples has been developed by optimizing the sample preparation, solvent extraction, sample clean-up and quantification procedures. The aflatoxins are extracted from a slurried palm kernel sample with an acetone-water (80 + 20, v/v) mixture and the crude extract is cleaned up by solid-phase extraction using a phenyl bonded phase cartridge. The extract is passed through the cartridge with a water-methanol (93 + 7) mixture. Subsequent elution of the aflatoxins retained on the cartridge is achieved with a 3 ml aliquot of chloroform. The aflatoxin content of the eluate is quantified using a bi-directional high-performance thin-layer chromatography procedure. A critical evaluation of the proposed method was carried out by statistical comparison with the British Standard Method. The proposed procedure was shown to be more efficient and precise. Consistent recoveries of over 90% were achieved from spiked palm kernel extracts and detection limits were found to be 3.7, 2.5, 3.0 and 1.3 micrograms kg-1 for AFB1, AFB2, AFG1 and AFG2 aflatoxins, respectively.     

Analysis of aflatoxins in nonalcoholic beer using liquid–liquid extraction and ultraperformance LC‐MS/MS

Aflatoxins AFB1, AFB2, AFG1, and AFG2 are toxic secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus and posses a potential threat to food safety. In the present work, liquid–liquid extraction and ultraperformance LC‐MS/MS method has been applied for the determination of four naturally occurring aflatoxins AFB1, AFB2, AFG1, and AFG2 in nonalcoholic beer. Aflatoxins extraction from nonalcoholic beer was carried out using liquid–liquid extraction procedure. The effects of solvent‐types were studied to obtain maximum recovery of the target analytes with minimum contamination. Among different solvents, the aflatoxins extraction was best achieved using ethyl acetate. The obtained recoveries were ranged from 85 to 96% with good quality parameters: LOD values between 0.001 and 0.003 ng/mL, linearity of the calibration curve (r² > 0.999), and repeatability (run‐to‐run) and reproducibility (day‐to‐day) precisions with RSDs lower than 5% (n = 5) achieved at 0.50 ng/mL concentration. The optimized liquid–liquid extraction in combination with ultraperformance LC‐MS/MS was applied successfully to the analysis of AFB1, AFB2, AFG1, and AFG2 aflatoxins in 11 nonalcoholic beers and were detected up to 15.31 ng/L in some of the samples.     

Determination of aflatoxins in animal feeds by liquid chromatography/tandem mass spectrometry with isotope dilution

The objective of the present study is to develop a simple, fast method for detection of aflatoxins in animal feeds. Simultaneous quantitation of four aflatoxins (AFB(1), AFB(2), AFG(1) and AFG(2)) in animal feeds was achieved in a single liquid chromatography/tandem mass spectrometry (LC/MS/MS) run. The solid-phase extraction cleanup step is eliminated with the stable isotope dilution method. Matrix effects were observed and overcome by isotope dilution. The method was tested in a variety of animal feed matrices and proved to be accurate and reliable. Method ruggedness tests resulted in recoveries of 78% to 122% with an intra-day assay precision of 2% to 15% and an inter-day assay precision of 3% to 17%. These results indicate that this method is suitable for quantitation of aflatoxins in animal feeds.