贝类中大田软海绵酸的液相色谱-串联质谱优化测定法

目的建立测定贝类组织中腹泻性贝类毒素大田软海绵酸(okadaic acid,OA)的优化高效液相色谱-串联质谱方法。方法样品经0.125 mol/L盐酸性水溶液提取,乙酸乙酯萃取,HLB固相萃取小柱净化,采用液相色谱-串联质谱进行检测。结果以80%甲醇-水为流动相等度洗脱,流速为0.3 m L/min,柱温为35℃,选择正离子扫描和多反应监测(MRM)模式进行分析,OA在2~200μg/L范围内线性关系良好。采用本研究改进的前处理方法,4个添加水平下的回收率为90.5%~99.6%,高于采用行业标准SN/T2269-2009前处理方法的回收率(81.3%~87.5%),相对标准偏差小于10%,方法定量限(以S/N≥10计)为1.0μg/kg。成功应用本方法检测了湛江市市售的7种贝类样品,未检出OA。结论该优化方法灵敏度高,操作较简便,适合于多种贝类样品中OA的检测。     

神经性贝类毒素免疫亲和柱的制备与应用

通过纯化PbTX-2单克隆抗体,以琼脂糖凝胶(sepharose 4B)为载体制备神经性贝类毒素(NSP)免疫亲和柱,并建立NSP的免疫亲和柱净化-液相色谱-串联质谱分析方法。样品以含80%甲醇水溶液提取,PBS缓冲液稀释,经过NSP免疫亲和柱净化和富集后进行LCMS/MS测试分析。同时对上样液、淋洗液、洗脱液等亲和柱参数进行优化。结果表明:NSP免疫亲和柱对贝类样品有很好的净化作用,降低了贝类基质中脂肪、蛋白质、色素、分泌黏液等杂质干扰,提高了样品回收率。在40~800μg/kg范围内样品加标平均回收率为82.95%~112.95%,相对标准偏差为1.27%~2.94%。该NSP免疫亲和柱净化效果强、灵敏度高且受基质干扰小,适用于贝类中神经性贝类毒素的分析测定。     

免疫亲和层析-液相色谱-串联质谱法测定玉米和小麦中的赭曲霉毒素A

目的建立免疫亲和层析净化-液相色谱-串联质谱法测定食品中的赭曲霉毒素A的方法。方法玉米和小麦样品经50%甲醇水溶液(V:V)提取,免疫亲和柱净化后,采用液相色谱-串联质谱法进行测定,外标法定量。结果玉米、小麦添加浓度在1.0~10.0μg/kg时,回收率在70%~100%之间,变异系数小于10%,在2017年度法帕斯国际能力验证中(Food Analysis Performance Assessment Scheme),此方法测定样品中赭曲霉毒素A含量为2.8μg/kg,Z值为-0.4,统计结论为满意。结论该方法简单快速,灵敏度高,定量准确,适合于玉米和小麦中赭曲霉毒素A的检测。     

固相萃取-液相色谱-串联质谱法测定贝类中的脂溶性贝类毒素

目的建立了测定贝类中大田软海绵酸(OA)、鳍藻毒素(DTX1、DTX2)、紫贻贝毒素(YTX)、原多甲藻酸贝毒素(AZA1)、螺环内酯毒素(SPX1)6种脂溶性贝类毒素的固相萃取-高效液相色谱-串联质谱方法。方法匀浆贝类组织,用80%甲醇提取,Strata~(TM)-X固相萃取小柱净化,0.3%氨水甲醇溶液洗脱,离心超滤管离心纯化。采用XTerra MS C_(18)柱(150 mm×2.1 mm,35μm)分离,以含6.7 mmol/L氨水的90%乙腈-水溶液为流动相进行梯度洗脱,选择多反应监测模式检测,正、负离子切换扫描,基质标准校正外标法定量。结果 6种脂溶性贝类毒素的定量限为0.2~1.0μg/kg,在相应浓度范围内线性良好,相关系数均0.995;低、中、高3个添加水平的平均加标回收率在78.8%~116%之间;相对标准偏差(RSD)为3.8%~14.5%。应用建立的方法对多份贝类样品进行分析,均未检出目标组分。结论方法选择性、灵敏性和准确度高,适用于贝类产品中脂溶性贝类毒素的确证及定量分析。     

基质分散固相萃取净化-亲水液相色谱-串联质谱法检测织纹螺与贝类中河鲀毒素

目的针对海产品常见中毒原因分析需求,建立基质分散固相萃取净化-亲水液相色谱-串联三重四极杆质谱(HILIC-MS/MS)快速定性定量检测织纹螺和贝类中河鲀毒素的新方法。方法 1.0 g样品经0.1%乙酸溶液沸水浴提取后,用50 mg亲水亲油平衡填料(HLB)和5 mg石墨化碳黑(GCB)吸附剂吸附净化,最后经乙腈蛋白沉淀后过0.22μm聚四氟乙烯(PTFE)滤膜,亲水液相色谱柱(150 mm×2.0 mm,3μm)分离,电喷雾离子化,选择反应监测(SRM)模式检测,基质匹配外标法定量。结果在2.0~40.0 ng/ml浓度范围内,河鲀毒素呈现良好的线性关系,相关系数r~2≥0.999;以3倍基线噪声所对应的浓度为检出限时,河鲀毒素的方法检出限可达10.0μg/kg;在25、100和200μg/kg的加标水平时,方法回收率为74.2%~87.9%,相对标准偏差为2.3%~9.1%。应用本方法对浙江沿海地区市售织纹螺和贝类样品进行检测,15份织纹螺中有14份检出河鲀毒素,检出率为93.3%,含量范围为0.04~15.75 mg/kg,60份贝类样品均未检出河鲀毒素。结论该检测方法准确、快速、易操作,能满足典型海产品中河鲀毒素的公共卫生应急检测或日常监测要求。     

免疫亲和净化-超高效液相色谱串联质谱法同时测定猪肉和鸡蛋中的12种磺胺类药物

建立了猪肉和鸡蛋中12种磺胺类药物的免疫亲和净化-超高效液相色谱串联质谱的确证方法。样品用超声提取后,直接过磺胺类药物免疫亲和净化柱净化;氮气吹干后用1∶9（v/v）的甲醇/水溶液定容,超高效液相色谱-串联质谱（UPLC-MS/MS）测定,电喷雾正离子（ESI＋）、多反应模式下监测;实验结果表明,样品中磺胺类药物浓度在10～200μg/kg范围内时与其峰面积成良好线性关系,仪器检出限为0.4～2.0μg/L,方法的检出限为1.0～5.0μg/kg,3个加标水平下平均回收率为67%～100%,相对标准偏差为0.9%～10.0%,符合痕量分析的要求。     

食品中黄曲霉毒素B_1的液相色谱-串联质谱测定法

建立了食品中黄曲霉毒素B1残留量的超高效液相色谱-串联质谱的检测方法。样品经乙腈+水(84+16)提取后,经多功能净化柱净化,超高效液相色谱-串联质谱法检测。本方法定量限为1μg/kg,线性范围为1~20 ng/mL;在黄曲霉毒素B1添加水平为1~10μg/kg时,在玉米样品中的回收率为95%~105%;在酱油样品中的回收率为96%~106%。     

超高效液相色谱-串联质谱法快速检测水产品中喹乙醇及其代谢物3-甲基-喹噁啉-2-羟酸的残留

建立了水产品中喹乙醇(OQX)及其代谢物3-甲基-喹噁啉-2-羟酸(MQCA)的超高效液相色谱串联质谱快速测定方法。试样经乙酸乙酯+乙腈(1+1,V/V)液液萃取提取和净化后,BEH C18UPLC进行分离,多反应选择离子检测。方法的回收率和变异系数分别在62.5%~91.4%和2.6%~11.8%之间。本方法对水产品中喹乙醇和3-甲基喹噁啉-2-羧酸的检测限均为1.0μg/kg。     

超高效液相色谱-串联质谱法测定普洱茶中赭曲霉毒素A

目的 建立超高效液相色谱-串联质谱对普洱茶中赭曲霉毒素A进行测定的分析方法。 方法 普洱茶样品采用乙腈/水(7:3,v/v)提取,PriboFast Multi-Toxin IAC免疫亲和净化柱净化,超高效液相色谱串联质谱进行测定分析,采用内标法定量。 结果 赭曲霉毒素A在浓度5.32-99.50μg.L_^-1范围内具有良好的线性关系,相关系数为0.9993,3个加标水平下的回收率为92.5%~95.6%, 相对标准偏差为2.18%~3.25%,检出限为0.10μg.kg_^-1。普洱茶样品中的赭曲霉毒素A均为未检出。 结论 普洱茶中复杂基质的存在对赭曲霉毒素A的测定有干扰,应采用免疫亲和净化柱净化处理,该方法具有较高的灵敏度及准确度,适用于普洱茶中赭曲霉毒素A的实际检测。     

液相色谱-串联质谱法检测动物源性食品中 7种抗病毒类药物残留

目的建立动物源性食品中7种抗病毒类药物残留的液相色谱-串联质谱测定方法。方法动物源性食品中的抗病毒类药物经甲醇-1%三氯乙酸(1:1,V:V)提取,通过固相萃取柱净化、浓缩后,在正离子模式下用液相色谱-串联质谱法检测。结果 7种抗病毒类药物检测限为0.3~1.5μg/kg,定量限为1.0~5.0μg/kg。在0.1~100μg/kg浓度范围内线性关系良好,相关系数r0.99。在1.0、5.0、10.0μg/kg三个浓度添加水平下,该方法的平均回收率为87.2%~121.4%,相对标准偏差为0.6%~8.4%(n=6)。结论本方法专属性强、准确性好、灵敏度高,适用于动物源性食品中抗病毒类药物残留的检测。     

免疫亲和柱净化-UPLC-MS/MS测定鱼虾肉中的3 种氨基糖苷类抗生素

将庆大霉素（gentamicin,GEN）、卡那霉素（kanamycin,KAN）和安普霉素（apramycin,APR）的抗体同时偶联到溴化氰活化的琼脂糖凝胶上,制备成复合型免疫亲和柱（immunoaffinity column,IAC）。建立鱼虾肉中3 种氨基糖苷类抗生素的免疫亲和柱净化-超高效液相色谱-串联质谱分析方法。采用BEH Amide（100?mm×2.1?mm,1.7?μm）色谱柱分离,以0.05%甲酸溶液和乙腈为流动相梯度洗脱,电喷雾正离子多反应模式监测。结果表明,所制备的IAC对GEN、KAN和APR的柱容量分别为1?127、1?368、925?ng/mL,洗脱液选用0.1%甲酸-甲醇溶液。GEN的线性范围为80.0～500?μg/L,KAN和APR的线性范围为20～500?μg/L,相关系数均大于0.995。鱼虾肉基质中3?种物质的平均回收率为71.7%～96.8%,相对标准偏差为4.2%～10.9%（n=6）,检出限和定量限分别为10～40?μg/kg和20～80?μg/kg。为水产品中氨基糖苷类药物残留监控提供一种有效的技术手段。     

Comparative Toxicity and Paralytic Shellfish Poisoning Toxin Profiles in the Mussel Mytilus galloprovincialis and the Oyster Crassostrea gigas Collected from a Mediterranean Lagoon in Tunisia: A Food Safety Concern

Edible shellfish Mytilus galloprovincialis and Crassostrea gigas have been investigated for the paralytic shellfish poisons using mouse bioassay and high performance liquid chromatography with fluorescence detection. Paralytic shellfish poisons toxins were detected in mussels and oysters from September 2007 to May 2008. The level of paralytic shellfish poisons toxins in mussels reached the maximum in November with 832.9 μg saxitoxin-eq/100 g tissue. In oysters, toxins were detected with a maximum of 11.2 μg saxitoxin-eq/100 g tissue. The toxin high performance liquid chromatography profiles in mussels and oysters revealed the dominance of gonyautoxin 5 and N-sulfocarbamoyl-gonyautoxin-2 and -3 (C1-2), whereas GTX1-4, saxitoxin, and neosaxitoxin were found at low amounts. Overall, levels of paralytic shellfish poisons toxins were 20–70 times greater in mussels than in oysters. This is the first report on the qualitative and quantitative paralytic shellfish poisons content of M. galloprovincialis and C. gigas from a shellfish farming lagoon in Tunisia.     

Analysis of sterigmatocystin in cereals,animal feed,seeds, beer and cheese by immunoaffinity column clean-up and HPLC and LC-MS/MS quantification

A method is reported for the analysis of sterigmatocystin in various food and feed matrices using a commercial sterigmatocystin immunoaffinity column (IAC) for sample clean-up prior to HPLC analysis by UV with mass spectrometric detection (LC-MS/MS). Cereals (wheat, oats, rye, maize and rice), sunflower seeds and animal feed were spiked with sterigmatocystin at levels from 0.75 to 50 µg kg^?1 to establish method performance. Using acetonitrile/water extraction followed by IAC clean-up, and analysis by HPLC with detection at 325 nm, recoveries ranged from 68% to 106%, with repeatability from 4.2% to 17.5%. The limit of quantification with UV detection in these matrices was 1.5 µg kg^?1. For the analysis of beer and cheese the sample preparation prior to IAC clean-up was changed to accommodate the different properties of the matrix, prior to analysis by LC-MS/MS. For beer and cheese spiked at 5.0 µg kg^?1 the recoveries were 94% and 104%, and precision (RSDs) were 1.9% and 2.9% respectively. The limits of quantification by LC-MS/MS in beer and cheese were 0.02 and 0.6 µg kg^?1 respectively. The sterigmatocystin IAC was demonstrated to provide an efficient clean-up of various matrices to enable this mycotoxin to be determined by either HPLC with UV detection or LC-MS/MS.     

Immunoaffinity removal and immunoassay for rhodamine B in chilli powder

A rapid and simple immunoassay and a sol–gel‐based immunoaffinity chromatography (IAC) purification method for Rhodamine B (RB) were developed using spiked chilli powder. A polyclonal antibody against RB was generated by immunisation of rabbits with an immunogen hapten. An enzyme‐linked immunosorbent assay (ELISA) was developed that achieved a 50% inhibition (IC₅₀) value of 0.94 ± 0.05 ng mL^?1. The limit of detection of the ELISA method was 1 ng g^?1 in chilli powder. For the IAC, recovery was 68.1–86.2% at 1 ng g^?1 and 72.6–89.3% at 5 ng g^?1 in spiked chilli powder. Fortified samples were analysed by high performance liquid chromatography–mass spectrometry (HPLC–MS) after IAC purification, and the results showed a good agreement between the two methods. The ELISA could be a convenient tool for screening RB residue in foods, and the IAC cleanup procedure coupled with HPLC–MS could be an effective alternative method for the determination of RB in various substances.     

Detection of DNA-bound advanced glycation end-products by immunoaffinity chromatography coupled to HPLC-diode array detection

Sugars and sugar degradation products are formed during food processing, but also endogenously in vivo. In vitro, nucleosides and DNA react readily with these carbonyl compounds during the formation of the two diastereomers of N(2)-carboxyethyl-2'-deoxyguanosine (CEdG(A,B)), leading to a loss of DNA integrity. Only little is known about DNA glycation in vivo and about the influence of nutrition on CEdG formation. In this study, we developed a sensitive method to analyze DNA glycation by HPLC. For this purpose, immunoaffinity chromatography (IAC) using a polyclonal antibody against N(2)-carboxyethylguanine (CEguanine) was coupled to HPLC-DAD. In some samples, peak identity was confirmed by LC-MS/MS. The recovery of CEguanine from the IAC columns was 52.5% +/- 3.6 (n = 4). Thus, it was possible for the first time to detect CEdG(A,B), N(2)-carboxyethylguanosine (CEG(A,B)), and CEguanine in 11 human urine samples. However, due to imprecision of IAC, valid quantification of the adducts could not be achieved. Furthermore, CEdG was also detected in the DNA of cultured human smooth muscle cells (SMCs) and bovine aorta endothelium cells (BAECs). In BAECs, CEdG(A,B) were found by HPLC-DAD and LC-MS/MS after immunoaffinity purification, whereas in SMCs DNA-advanced glycation end-products were only detected with the more sensitive LC-MS/MS method.     

Natural occurrence of ochratoxin A in wolfberry fruit wine marketed in China

Wolfberry fruit wine (WFW) is widely used as a global functional food to improve the immune system and prevent human disease. A total of 36 bottled WFWs were randomly collected in China between 2005 and 2010. Samples were analysed for the presence of ochratoxin A (OTA) using immunoaffinity column (IAC) clean-up and high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Positive results were confirmed by liquid chromatography–electrospray ionisation–tandem mass spectrometry (LC-ESI-MS/MS). The limit of detection (LOD), based on a signal-to-noise ratio of 3, was 0.05?ng?mL^–1. Recoveries ranged from 78.3% to 94.7% and relative standard deviations from 1.1% to 4.3% within the spiking range of 0.2–20?ng?mL^–1. OTA was detected in one sample, below the maximum allowable limit as established by the European community.     

双固相萃取柱净化-超快速液相色谱-串联质谱法同时测定贝类组织中全氟羧酸及其前体物质

建立同时测定贝类中13种全氟羧酸类化合物、6种氟调聚饱和酸和3种氟调聚不饱和酸的超快速液相色谱-串联质谱分析方法。样品经90%乙腈溶液超声提取,Oasis WAX和Envi-Carb双固相萃取柱净化,Kinetex XB-C_(18)色谱柱(2.1 mm×100 mm,2.6μm)分离,多反应监测负离子模式扫描,同位素内标法定量。22种目标物在各自相应质量浓度范围内线性良好,相关系数不低于0.995,定量限为0.03~1.67 ng/g。基质加标回收率在63.05%~127.18%之间,相对标准偏差为4.70%~17.1%。本方法实现了复杂贝类基质(肌肉、肝脏、外套膜、鳃、性腺等)中PFCAs及其前体物质的同时测定,采用双柱净化方式,大大降低了杂质成分的干扰,部分化合物的灵敏度优于现有方法,适用于贝类样品中PFCAs及其前体物质的监控分析,为研究PFCAs前体物质的生物转化提供了新技术手段。     

免疫亲和柱净化-超高效液相色谱-串联质谱检测鱼虾中3-甲基-喹噁啉-2-羧酸

将特异性强的免疫亲和柱应用到3-甲基-喹噁啉-2-羧酸（methyl-3-quinoxaline-2-carboxylic acid,MQCA）的净化中,建立鱼虾中MQCA的免疫亲和柱净化-超高效液相色谱-串联质谱的快速分析方法。匀质好的样品经2 mol/L盐酸溶液酸解后,将提取液pH值调节至7～8,经过免疫亲和柱富集和净化后,采用超高效液相色谱-串联质谱测定,外标法定量。以甲醇-0.1%甲酸溶液为流动相,梯度洗脱分离,电喷雾正离子多反应监测模式监测。结果显示,水产品中MQCA在1.0～50.0 ng/mL范围内呈良好线性,线性相关系数大于0.995,定量限为1.0 μg/kg。MQCA在1.0、5.0 μg/kg和20.0 μg/kg 3 种添加水平条件下的加标回收率为74.2%～86.5%,相对标准偏差小于10%。结果表明本方法重复性好、灵敏度高,适合水产品中MQCA的实际测定。     

Screening for the presence of lipophilic marine biotoxins in shellfish samples using the neuro-2a bioassay

The neuro-2a bioassay is considered as one of the most promising cell-based in vitro bioassays for the broad screening of seafood products for the presence of marine biotoxins. The neuro-2a assay has been shown to detect a wide array of toxins like paralytic shellfish poisons (PSPs), ciguatoxins, and also lipophilic marine biotoxins (LMBs). However, the neuro-2a assay is rarely used for routine testing of samples due to matrix effects that, for example, lead to false positives when testing for LMBs. As a result there are only limited data on validation and evaluation of its performance on real samples. In the present study, the standard extraction procedure for LMBs was adjusted by introducing an additional clean-up step with n-hexane. Recovery losses due to this extra step were less than 10%. This wash step was a crucial addition in order to eliminate false-positive outcomes due to matrix effects. Next, the applicability of this assay was assessed by testing a broad range of shellfish samples contaminated with various LMBs, including diarrhetic shellfish toxins/poisons (DSPs). For comparison, the samples were also analysed by LC-MS/MS. Standards of all regulated LMBs were tested, including analogues of some of these toxins. The neuro-2a cells showed good sensitivity towards all compounds. Extracts of 87 samples, both blank and contaminated with various toxins, were tested. The neuro-2a outcomes were in line with those of LC-MS/MS analysis and support the applicability of this assay for the screening of samples for LMBs. However, for use in a daily routine setting, the test might be further improved and we discuss several recommended modifications which should be considered before a full validation is carried out.