超高效液相色谱-质谱联用法检测地理标志产品松江大米中8种真菌毒素的含量

建立超高效液相色谱-三重四极杆质谱法同时检测大米基质中8种真菌毒素的方法,对地理标志产品松江大米中真菌毒素的污染情况进行监测。大米样品经提取液乙腈水混合液（84:16,v:v）超声提取后,取部分提取液加入内标溶液,混匀后过多功能净化柱MycoSep229净化,采用Waters Acquity UPLC?BEH?C18色谱柱 (2.1 mm×50 mm, 1.7 μm),以0.1%（v:v）甲酸水溶液-乙腈作为流动相进行梯度洗脱,分离黄曲霉毒素B1（Aflatoxin B1, AFB1）、黄曲霉毒素B2（Aflatoxin B2, AFB2）、黄曲霉毒素G1（Aflatoxin G1,AFG1）、黄曲霉毒素G2（Aflatoxin G2, AFG2）、伏马毒素B1（FumonisinsB1, FB1）、伏马毒素B2（FumonisinsB2, FB2）、伏马毒素B3（FumonisinsB3, FB3）、赭曲霉毒素A（Ochratoxin A, OTA） 8种真菌毒素化合物,该方法采用电喷雾离子化正离子模式,以多反应监测方式进行。AFB1、AFG1、FB1、FB2、FB3、OTA 6种真菌毒素在0.5-15μg/L范围内线性良好,AFB2、AFG2在0.125-3.75μg/L范围内线性良好,线性相关系数r均大于0.999;8种化合物定量限(limit of quantifications, LOQs)范围为0.01-0.25 μg/kg,比国标中相同方法的定量限降低2-80倍不等;在低、中、高三水平加标,其回收率均在95%~120%范围内,相对标准偏差(relative standard deviations, RSDs)为1.5%~8.9% (N=6)。本方法前处理简单,方法利用率高,结果准确可靠,利用该方法检测的20批新上市松江大米中真菌毒素污染情况比较乐观,对人体的健康危害较低。     

UPLC-MS/MS法测定玉米种13种真菌毒素

建立了超高压液相色谱串联质谱法（UPLC-MS/MS）测定玉米中脱氧雪腐镰刀菌烯醇及其乙酰化衍生物、玉米赤霉烯酮、黄曲霉毒素B1/B2/G1/G2、伏马毒素B1/B2、赭曲霉毒素A、T-2和HT-2等13种真菌毒素的分析方法。样品采用乙腈︰水︰乙酸（80︰19︰1,体积比）提取后,经过稀释、离心和过滤的前处理操作即可进行仪器测定。结果表明,13种真菌毒素的定量限在1~200 μg/kg之间,三个浓度添加水平回收率为80%~114%,相对标准偏差为0.9%~10.9%,基体标准物质测定结果均在标准值±不确定度的范围内。     

重庆地区辣椒、花椒、八角中真菌毒素污染状况分析

目的 了解重庆地区辣椒、花椒和八角中真菌毒素污染状况。方法 采用随机抽样方法,在重庆地区盘溪、菜园坝和江津三个市场,抽取180批次香辛料样品,采用HPLC-MS/MS检测黄曲霉毒素（AFB1、AFB2、AFG1和AFG2）、赭曲霉毒素A（OTA）和伏马毒素（FB1和FB2）。结果 重庆地区辣椒、花椒和八角中的真菌毒素总检出率分别为60.0%、100%、96.7%。AFs和OTA是三种香辛料最主要的污染毒素,其中AFG2是最主要的黄曲霉代谢产物。盘溪市场的AFs污染总体情况稍好,菜园坝市场AFs污染最严重;江津市场的OTA污染最为严重。结论 香辛料中存在真菌毒素污染,有必要建立香辛料中真菌毒素的限量标准。     

超高效液相色谱-串联质谱测定芝麻酱中16种真菌毒素

建立了芝麻酱中16种真菌毒素(赭曲霉毒素A、T-2毒素、伏马菌素B2、伏马菌素B1、O-甲基杂色曲霉素、蛇形菌素、新茄镰孢菌醇、杂色曲霉素、黄曲霉毒素B1、黄曲霉毒素B2、黄曲霉毒素G1、黄曲霉毒素G2、曲酸、青霉酸、橘青霉素、黄曲霉毒素M1)多残留的超高效液相色谱-串联质谱(UPLCMS/MS)的检测方法。芝麻酱样品经乙腈-水-乙酸(80∶19∶1,体积分数,下同)溶液提取,QuEChERS方法净化后,以含0.1%甲酸的水溶液与乙腈为流动相,经ACQUITY UPLC BEH C18色谱柱(2.1mm×50mm,1.7μm)分离,以多级反应监测(MRM),外标法定量。结果表明:16种真菌毒素的检出限为0.03~1.5μg/kg,定量限为0.10~4.0μg/kg;线性范围在0.10~200μg/kg内各成分的线性相关系数均大于0.991;样品在定量限1倍、2倍和10倍3个添加水平下的平均回收率为70.7%~99.2%,相对标准偏差(RSD)为3.26%~10.5%。该方法简便、灵敏、快速,可用于芝麻酱中多种真菌毒素污染的监控分析。     

固相萃取柱净化-超高效液相色谱-串联质谱法快速测定液态乳中14 种真菌毒素

建立使用固相萃取柱净化液态乳中14 种真菌毒素（黄曲霉毒素B1、黄曲霉毒素B2、黄曲霉毒素G1、黄曲霉毒素G2、黄曲霉毒素M1、赭曲霉毒素A、橘霉素、T-2毒素、杂色曲霉素、伏马毒素B1、伏马毒素B2、玉米赤霉烯酮、脱氧雪腐镰刀菌烯醇、青霉酸）多残留的超高效液相色谱-串联质谱检测方法。样品经含0.1%甲酸-乙腈沉淀蛋白和提取,固相萃取柱Oasis PRiME HLB净化后,以0.1%甲酸溶液与乙腈为流动相,经ACQUITY UPLC HSS T3色谱柱（2.1?mm×100?mm,1.8?μm）分离,梯度洗脱,采用电喷雾-正离子多反应监测模式,外标法定量。结果表明：14?种真菌毒素的定量限（RSN≥10）为0.5～5?μg/kg,高、中、低3?个添加水平时,平均回收率为67.7%～112.7%,相对标准偏差为0.43%～7.28%。该方法的检测速度快,净化效果较好,基质干扰较少,灵敏度高,结果准确、可靠,可用于液态乳中真菌毒素的检测分析。     

烟台市售谷类及其制品中真菌毒素污染状况调查分析

为了解烟台市谷类及其制品中真菌毒素的污染状况,采用随机采样方法,2014年4月~2017年9月在烟台辖区11个监测点采集4类225种样本,按照《国家食品污染物和有害因素风险监测工作手册》规定的真菌毒素标准操作程序,进行15种真菌毒素的检测。结果表明,烟台市玉米及其制品、小麦及其制品普遍存在不同种类真菌毒素污染,而大米、小米均未检出,检出率为52.44%,超标率2.22%。小麦及其制品中主要检出15-乙酰脱氧雪腐镰刀菌烯醇(15-acetyldeoxynivalenol,15-Ac-DON)、脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)、伏马菌素B1,检出率分别为0.8%、55.2%、0.24%,伏马菌素B1仅存在小麦(原粮)中,15-Ac-DON则仅存在湿面条中。小麦及其制品中DON均有检出,均值73.86μg/kg,馒头、面条(干、湿)、面包中DON的样本检出率100%,小麦粉为40%,小麦(原粮)为20%。玉米及其制品中真菌毒素检出率为53.85%,主要存在伏马菌素(B1、B2、B3)、玉米赤霉烯酮(Zearalenone,ZEN)、DON、15-Ac-DON、赭曲霉毒素A(Ochratoxin A,OTA)、黄曲霉毒素B1(Aflatoxin B1,AFB1)、黄曲霉毒素B2(Aflatoxin B2,AFB2),检出率分别为32.97%、19.78%、26.37%、21.98%、17.58%、13.19%、8.79%、4.40%、2.20%;而T-2毒素、黄曲霉毒素G1(Aflatoxin G1,AFG1)、黄曲霉毒素G2(Aflatoxin G2,AFG2)检出率均为1.10%;玉米油中仅检出ZEN,检出率51.85%,均值126.68μg/kg。小麦及其制品和玉米其制品中均在毒素多重混合污染同一样本状况,2种及以上真菌毒素的多重污染率13.33%,3种毒素多重污染率最高为5.33%,玉米及其制品多重污染水平高于小麦及其制品。     

冷冻-离心净化-高效液相色谱法测定植物油中黄曲霉毒素B1

通过冷冻-离心净化,建立了高效液相色谱定量测定植物油中黄曲霉毒素B1的方法,并将其用于测定市场上30批植物油产品中黄曲霉毒素B1的含量。以水/乙腈溶液为提取剂对植物油中黄曲霉毒素B1进行萃取,低温冷冻固化植物油,冷冻离心使植物油和提取液分离、净化提取液,经衍生后上液相色谱进行定量分析。优化的乙腈/水提取液配比为90:10,低温冰箱冷冻温度为-12 ℃,冷冻离心转速为12000 r/min、离心力约为1.4万 × g,以水浴加热的方式进行衍生。方法的定量检出限为0.02 μg/kg,校准曲线回归方程为y=2.321987x＋0.001377,相关系数（R2）为0.9997,在0.10～5.0 μg/L范围内线性关系良好。当样品中黄曲霉毒素B1添加量为0.5、1.0、5.0 μg/kg时,平均回收率为80.2%～93.2%,相对标准偏差为2.9%～4.7%（n=6）,均优于免疫亲和柱净化处理的结果。市售植物油产品中黄曲霉毒素B1的浓度范围为< LOD至5.72 μg/kg,均低于GB 2761—2017中对该指标的限值,花生油和玉米油中黄曲霉毒素B1均有检出,油茶籽油和核桃油中黄曲霉毒素B1均低于检出限。该方法样品前处理简便、稳定性好、检出限低,适合植物油中黄曲霉毒素B1的批量检测。     

山东省玉米真菌毒素污染状况调查及分析

为掌握山东省玉米的真菌毒素污染状况,评估污染带来的安全风险,为加强真菌毒素污染防控提供依据,采集了山东省玉米主产县2013年~2014年收获和储藏的玉米样品共520批次,采用液相色谱—飞行时间质谱联用仪(UPLC-Q-TOF)方法检测了玉米中黄曲霉毒素(AFB_1、AFB_2、AFG_1、AFG_2)、伏马毒素(FB_1、FB_2、FB_3)、呕吐毒素(DON)和玉米赤霉烯酮(ZEN)的污染水平。结果表明,AFB1、AFB2、AFG1在玉米中检出率分别为18.08%、7.88%、0.77%,平均含量分别为7.62、0.60、0.05μg/kg;FB1、FB2、FB3检出率分别为92.50%、88.08%、83.85%,平均含量分别为1 798.69、531.83、197.71μg/kg;DON检出率为26.35%,平均含量为240.44μg/kg;ZEN检出率为14.62%,平均含量为74.90μg/kg;AFG2未检出。调查结果还表明,伏马毒素在所测样品中污染最为严重,超标率达33.46%;单一样品受多种毒素混合污染的情况较严重。     

94份玉米中6类真菌毒素检测及污染情况分析

建立了玉米的一步法提取6类真菌毒素同时检测的分析方法，共分析了94份玉米中6类真菌毒素的污染情况及地域分布情况，为监测饲料质量提供技术指导。称取的样品添加6类真菌毒素同位素内标，以84%乙腈水和50%甲醇水作为提取试剂，以2 mmol/L乙酸铵0.1%甲酸水溶液和甲醇/乙腈和水为流动相梯度洗脱，采用液相色谱-串联质谱进行检测。94份玉米中6类真菌毒素的检出率为98%,单种毒素检出率最高的是伏马毒素B₁和B₂,高达88%,呕吐毒素和赭曲霉毒素A检出率最低，均未检出。伏马毒素B₁和B₂、黄曲霉毒素B₁、玉米赤霉烯酮和呕吐毒素的最高残留量分别是89.1 mg/kg、76.4μg/kg、3.95×10³ mg/kg和7.0 mg/kg。地域分布上具有分布范围广，污染较严重的特点。建立的6类真菌毒素检测方法操作简单、结果准确，结果分析对玉米中真菌毒素污染检测和防控具有重要意义。     

免疫快速同步检测玉米中五种真菌毒素胶体金试纸条的构建和应用

玉米作为重要的粮食和饲料来源，容易受到多种真菌毒素的污染，给居民健康和养殖业造成严重的危害。本文优化了适合五种真菌毒素（黄曲霉毒素B1、伏马毒素、T-2毒素、脱氧雪腐镰刀菌烯醇和玉米赤霉烯酮）同时提取的样品前处理方法，并构建了五检测线胶体金试纸条，检测结果可以通过肉眼定性，结合Image J软件可以进行定量分析，并应用于实际玉米样品检测。结果表明，最佳提取条件为90%乙腈/水，涡旋20 min，样品的添加回收率为71.9%-113.3%，相对标准偏差为0.9%-7.5%；测定基质添加样品建立标准曲线，通过肉眼判定得到五种真菌毒素的消线值分别为80.0、1000.0、100.0、400.0和200.0 μg/kg；结合Image J 软件提取多重检测试纸条的检测线灰度值，结果表明当AFB1、FB1、T-2、DON和ZEN的浓度为8.0、20.0、10.0、40.0、20.0 μg/kg时，各真菌毒素浓度对应的检测线显色值比空白对照显色值低。最后，通过检测11个实际玉米样品，结果表明部分玉米样品受到了不同程度的AFB1、DON和ZEN的污染。因此，本研究开发的免疫快速同步检测玉米中五种真菌毒素胶体金试纸条可以用于玉米中真菌毒素的现场快速筛查。     

Natural occurrence of aflatoxins (B1 and M1) in feed,plasma and raw milk of lactating dairy cows in Beja,Tunisia, using ELISA

Beja is an agricultural area in northwest Tunisia. It contributes to national needs by offering cereals and milk to the market for human and animal consumption. A small number of studies on mycotoxin occurrence in feedstuffs and raw milk from lactating dairy cows in this region are available. Therefore, 226 samples were collected from farms and local markets during November 2008 until April 2010. Samples consisted of 112 raw cow milk, 56 blood from lactating cows and 58 feed destined for dairy cows. Plasma and feed were analysed for aflatoxin B₁ (AFB₁). Milk samples were analysed for aflatoxin M₁ (AFM₁). All samples were treated using a simultaneous methanolic-aqueous extraction, followed by immunoaffinity column clean-ups and were investigated by competitive enzyme-linked immunoabsorbent assay (ELISA). Recoveries were 80%–95% and 81%–92% for AFB₁ and AFM₁, respectively, while the limit of detection (LOD) was 0.01?µg/kg or µg/l for both mycotoxins. Results revealed the presence of AFB₁ in 84.4% of the feed samples (mean 18.7?±?1.4?µg/kg), and 39.2% of the plasma-examined samples (median 7.1?±?1.0?µg/l) were found to be contaminated at levels higher than the Tunisian and the European Union (EU) limit for dairy animals, which are 20 and 5?µg/kg in animal feed, respectively. AFM₁ was detected in 60.7% of the cow raw milk samples examined (median 13.6?±?1.4?µg/l). Contaminated levels were higher than the EU limit of 0.05?µg/l. It was concluded that more precaution should be taken on hygiene controls in order to prevent fungal contamination.     

Aflatoxin B1, ochratoxin A and zearalenone in sorghum grains marketed in Tunisia

A total of 64 samples of sorghum (37 Tunisian sorghum samples and 27 Egyptian sorghum samples) were collected during 2011–2012 from markets in Tunisia. Samples were analysed for contamination with aflatoxin B1, ochratoxin A and zearalenone by High-Performance Liquid Chromatography Coupled with Fluorescence Detection (HPLC-FLD). Aflatoxin B1 was found in 38 samples in the range 0.03–31.7 µg kg^?1. Ochratoxin A was detected in 24 samples with concentrations ranging from 1.04 to 27.8 µg kg^?1. Zearalenone was detected in 21 samples and the concentration varied between 3.7 and 64.5 µg kg^?1. ANOVA analysis of the influence of the country of origin on the incidence and concentration of mycotoxins in the samples studied showed no significant difference (P > 0.05) between the two batches of samples for each of the three mycotoxins studied. The studied mycotoxins contaminate sorghum and may also co-exist because of the diversity of the mycobiota in this cereal.     

Mycotoxin contamination of sorghum and its contribution to human dietary exposure in four sub-Saharan countries

This research aimed at evaluating the safety, and the type, level and prevalence of mycotoxins in grain sorghum of four sub-Saharan African (SSA) countries (Burkina Faso, Ethiopia, Mali and Sudan). A multi-analyte LC-MS/MS method for quantification of 23 mycotoxins (nivalenol, deoxynivalenol, fusarenon X, neosolaniol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, diacetoxyscirpenol, roquefortine C, HT-2 toxin, alternariol, T-2 toxin, FB1, FB2, FB3, zearalenone, aflatoxin G₁, aflatoxin G₂, aflatoxin B₁, aflatoxin B₂, sterigmatocystin, OTA, altenuene, alternariol monomethylether) was applied to different sorghum matrices. Of the 1533 analysed samples, 33% were contaminated with at least one of the following mycotoxins: aflatoxins, fumonisins, sterigmatocystin, Alternaria toxins, OTA and zearalenone. Country of origin, colour, source and collection period of sorghum samples significantly influenced the type, level and prevalence of mycotoxins. Sterigmatocystin (15%), fumonisins (17%) and aflatoxins (13%) were the most prevalent. FB1 (274 ± 585 µg/kg) had the highest mean concentration followed by FB2 (214 ± 308 µg/kg) while diacetoxyscirpenol (8.12 ± 19.2 µg/kg) and HT-2 (11.9 ± 0.00 µg/kg) had the lowest concentrations. Neosolaniol, fusarenon-X, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, T-2 toxin, nivalenol and roquefortine C were not detected in any of the samples. Sudan had the lowest prevalence and mean concentration of all mycotoxins. Pink sorghum had the highest concentrations of fumonisins and aflatoxins. Mycotoxins from Aspergillus spp. and Alternaria spp. are the mycotoxins of concern in SSA grain sorghum with regard to prevalence, concentration and possible health risk from exposure. Based on the performed risk characterisation, daily consumption of sorghum containing aflatoxins, alternariol, alternariol monomethyl ether, sterigmatocystin and OTA could result in exceeding the established health-based guidance values for these toxins.     

Occurrence of aflatoxins (B1, B2, G1, G2) in herbal tea consumed in Turkey

Aflatoxin contents in 12 types of herbal teas were determined by high performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. Forty eight samples were collected from four local herbal shops in Manisa, Turkey. Of the 48 samples analyzed, 43 were aflatoxin positive. The highest concentration of aflatoxin (34.18 µg/kg) was determined in a sample of camomile tea. The occurrence of AFB1, B2, G1 and G2 was found in samples at levels of 54, 29, 71 and 46 %, respectively. Aflatoxin B1, B2, G1 and G2 contamination levels varied from 0 to 14.2, 0 to 12.4, 0 to 13.5 and 0 to 28.7 µg/kg, respectively. Aflatoxin was not detected in five samples consisting of linseed, lime and fennel tea.     

Multi-microbial metabolites in fonio millet (acha) and sesame seeds in Plateau State, Nigeria

We investigated 16 fonio millet and 17 sesame samples by LC/ESI–MS/MS for the spectrum of microbial metabolites contaminating these seeds. Forty-eight fungal and four bacterial metabolites were detected in fonio, while 28 fungal and two bacterial metabolites were found in sesame. Altogether, 55 metabolites were identified in both grains, 18 of which are reported for the first time to naturally occur in cereals and oil seeds. The metabolite concentrations reached 7,280 μg/kg in fonio for aurofusarin and 64,600 μg/kg in sesame for kojic acid. Aflatoxin contaminated 81 % of fonio samples at concentrations less than the 4 μg/kg maximum allowable limit (MAL) set by European Union (EU). In contrast, aflatoxin was not detected in sesame. Zearalenone levels exceeded the EU MAL (75 μg/kg) in one sample of fonio (987 μg/kg). About 62.5 % (30 out of 48) of the metabolites without regulations occurred in more than 50 % of samples of one or both seeds, while 3-nitropropionic acid, beauvericin, brevianamid F, curvularin, emodin, equisetin, macrosporin A, monocerin and tenuazonic acid were the most prevalent, occurring in all samples of either fonio, sesame or both. This is the first study reporting mycotoxin contamination in sesame in Nigeria and the broad range of microbial metabolites in millet and sesame.     

Aspergillus section Flavi and aflatoxins in dried figs and nuts in Algeria

The presence of Aspergillus section Flavi and aflatoxin (AF) contamination was investigated in 112 samples of peanuts, almonds and dried figs collected in Algeria. The occurrence of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) in different commodities has been determined with a sensitive method based on high performance liquid chromatography (HPLC) coupled with fluorescence detection with post-column photochemical derivatisation. Analytical results indicated that 28 samples of peanuts, 16 samples of almonds and 26 samples of dried figs contained detectable levels of AFs. A total of 69 samples (61.6%) were contaminated with AFB1 ranging from the limit of quantification to 174 µg kg^?1. AFB2 was found in 12 samples (10.7%) and varied from 0.18 to 193 µg kg^?1. Seven samples revealed AF concentrations lower than the limit of quantification. Eleven peanut and fourteen dried fig samples exceeded the European maximum limits for AFB1.     

Aflatoxins,ochratoxins and zearalenone in sorghum and sorghum products in Sudan

This survey examined 60 samples of sorghum and 30 samples of sorghum products from three states (Khartoum, Kordofan and Gadarif) of Sudan for aflatoxin B1, B2, G1 and G2 (AFB1, AFB2, AFG1, AFG2), ochratoxin A and B (OTA, OTB) and zearalenone (ZEN), using high performance liquid chromatography with fluorescence detection. The limits of detection and limits of quantification were in the range 0.01–0.6 µg kg^–1 and 0.03–2.0 µg kg^?1, respectively. The frequency of contaminated samples with AFB1 from Khartoum, Gadarif and Kordofan state was 38.1%, 22.2% and 23.8%, respectively. Only two samples of sorghum from Khartoum state were contaminated with OTA (3.3%). Concentrations of OTA and OTB were low and may not cause problems. No sample of sorghum or sorghum products was contaminated with ZEN. Some sorghum samples contained AFB1 concentrations above the European Union regulatory limits. The highest contaminated samples were found in Khartoum state.     

Determination of aflatoxins in peanut butter and sesame samples using high-performance liquid chromatography method

In this study, total number of samples analysed were 20 packages of sesame and 20 cans of peanut butter, which were collected from Ankara local markets, Turkey. Extraction and determination of aflatoxins have been made by immunoaffinity column technique and high-performance liquid chromatography (HPLC) method. Mean levels (±SE) of aflatoxins B₁, B₂, G₁ were found to be 15.756±3.129 ng/g, 1.232±0.244 ng/g and 9.689±1.005 ng/g, respectively in peanut butter samples. Regarding the sesame samples, mean level of aflatoxin G₁ was found to be 0.754±0.213 ng/g. Our data revealed that while aflatoxin levels found in sesame samples were within the Turkish Food Codex (TFC) values, for peanut butter samples, they were higher than the TFC values.     

Comparison of homogenization techniques and incidence of aflatoxin contamination in dried figs for export

To determine differences in mean aflatoxin contamination and subsample variance from dry and slurry homogenizations, 10 kg of six different, naturally contaminated dried fig samples were collected from various exporting companies in accordance with the EU Commission Directive. The samples were first dry-mixed for 5 min using a blender and sub-sampled seven times; the remainder was slurry homogenized (1 : 1, v/v) and sub-sampled seven times. Aflatoxin B₁ and total aflatoxin levels were recorded and coefficient of variations (CV) computed for all sub-samples. Only a small reduction in sub-sample variations, indicated by the lower CV values, and slight differences in mean aflatoxin B₁ and total aflatoxin levels were observed when slurry homogenization was applied. Therefore, 7326 dried figs, destined for export from Turkey to the EU and collected during the 2008 crop year, were dry-homogenized and tested for aflatoxins (B_1, B_2, G₁ and G₂) by immunoaffinity column clean-up using RP-HPLC. While 34% of the samples contained detectable levels of total aflatoxins (0.20–208.75 µg kg^?1), only 9% of them exceeded the EU limit of 4 µg kg^?1 in the range 2.0–208.75 µg kg^?1, respectively. A substantial increase in the incidence of aflatoxins was observed in 2008, most likely due to the drought stress experienced in Aydin province as occurred in 2007.     

Survey for co-occurrence of ochratoxin A and aflatoxin B1 in dried figs in Turkey by using a single laboratory-validated alkaline extraction method for ochratoxin A

A survey was carried out to determine the co-occurrence of ochratoxin A and aflatoxin B1 in dried figs from Turkey. Samples from two seasons of crops (2003 and 2004) intended for export to the European Union and the 2004 crop obtained from the domestic Turkish market were analyzed. Affinity column cleanup methods were employed for determining separately ochratoxin A and aflatoxin B1, but for ochratoxin A an alkaline extraction procedure was employed (in contrast to the conventionally employed acidic extraction), which gave consistently higher toxin recovery. In-house validation of the ochratoxin A method gave a limit of detection of 0.15 ng/g and a limit of quantification of 0.5 ng/g with a repeatability of 5.8% in the range 5 to 10 ng/g (with a mean recovery of 94% for spiked samples). Positive results for ochratoxin A were confirmed by liquid chromatography-mass spectrometry. For the 2003 export figs (58 samples), 7 samples contained only aflatoxin B1, 2 samples contained only ochratoxin A, and 2 samples contained both toxins (with maximum concentrations of 35.1 ng/g for aflatoxin B1 and 13.0 ng/g for ochratoxin A). Similarly for the 2004 export figs (41 samples), 16 samples contained only aflatoxin B1, 4 samples contained only ochratoxin A, and 2 samples contained both toxins (with maximum concentrations of 20.6 ng/g for aflatoxin B1 and 26.3 ng/g for ochratoxin A). Of 20 retail samples of dried figs from Turkey, only one sample contained ochratoxin A (2.0 ng/g) and none were contaminated with aflatoxin B1. This survey revealed a 14 to 15% incidence of occurrence of ochratoxin A for 2 years, which is higher than previously reported.