QuEChERS-HPLC-MS/MS法检测谷物源性运动食品中杂色曲霉毒素和黄曲霉毒素

建立一种快速、高效的QuEChERS-高效液相色谱-串联质谱（QuEChERS-HPLC-MS/MS）法测定谷物源性运动食品中的杂色曲霉毒素和黄曲霉毒素的方法。样品采用乙腈-水（85∶15,V/V）提取,经SiO2+C18净化后检测。以乙腈-0.15%甲酸为流动相,在质谱检测器的多反应监测模式下进行分析。结果表明,5种真菌毒素在0.1～10.0 ng/mL质量浓度范围内线性关系良好,相关系数（R2）为0.999 2～0.999 7,检出限为0.03～0.14 μg/kg,定量限为0.10～0.49 μg/kg,加标回收率为85.8%～99.4%,精密度试验结果的相对标准偏差（RSD）为2.72%～5.23%。该方法具有前处理简单、净化效果好、灵敏度高的优点,适用于谷物源性运动食品中杂色曲霉毒素和黄曲霉毒素的分析和定量检测。     

Occurrence and levels of mycotoxins and their metabolites in human breast milk associated to dietary habits and other factors: A systematic literature review, 1984–2015

BackgroundMany studies around the world reported the occurrence of many mycotoxins and their metabolites in human breast milk. However the contamination by aflatoxin M1 and ochratoxin A were the most investigated by several countries.Scope and approachTo scrutinize all papers reporting quantitative data on the prevalence and the levels of mycotoxins and their metabolites in breast milk, also the circumstances of exposure.A systematic literature search in Pubmed, Science direct and Google scholar databases were performed to identify relevant studies, published in English from 1984 through May 2015.Key findings and conclusion63 studies met the inclusion criteria and assessed the occurrence of 29 mycotoxins & their metabolites in breast milk, regarding 7194 subjects of 31 countries. The maternal dietary habits, the socio demographic status of the mother, the seasonal variations and the sensitivity of the analytical method were the factors related to the high concentrations of AFM1 and OTA in breast milk.Studies where contamination exceeds maximum limits and exhibit real risk of public health were highlighted.     

Determination of sterigmatocystin in cheese by high-performance liquid chromatography-tandem mass spectrometry

Different cheese samples produced in Latvia (eight) and Belgium (13) were analysed for their sterigmatocystin (STC) content. Only two (9.5%) of the samples were positive for STC with concentration levels of 1.23 and 0.52 µg kg^?1, respectively. Five (24%) samples contained STC above the limit of detection (0.03 µg kg^?1) but below the limit of quantification (0.1 µg kg^?1), A sensitive liquid chromatography-electrospray positive ionisation-tandem mass spectrometry (LC-MS/MS) method, which was previously developed for the analysis of STC in grains, was modified and applied to the analysis of STC in cheese. This method involved sample extraction with acetonitrile–water (90 : 10, v/v), defatting with n-hexane, solid-phase extraction, separation on a reversed-phase C₁₈ column, and STC detection by LC-MS/MS.     

仓储稻米中产柄曲霉素菌的分离鉴定及其产毒条件研究

将1份来自广东省韶关市仓储霉变稻米的稀释液接种至马铃薯葡萄糖琼脂(Potato Dextrose Agar,PDA)培养基上,利用平板划线法分离获得菌株,通过高效液相色谱-串联质谱对获得菌株的产柄曲霉素(Sterigmatocystin,STC)能力进行检测,结合形态学观察和rDNA-ITS序列分析对产毒素菌鉴定,并对其产STC菌株的产毒条件(培养基、培养天数、培养温度)进行考察。结果表明,该稻米中共分离到9种菌,其中Aspergillus jensenii可代谢合成STC,其最佳产毒培养基为大米培养基,最适温度为28℃,且在培养的第28天含量达到最大。该研究可为我国针对性的防控粮食中产毒性真菌污染提供基础性实验菌株,同时也有利于STC生物合成、代谢等工作的开展。     

高效液相色谱法测定小麦中的杂色曲霉毒素

目的:建立小麦中杂色曲霉毒素的高效液相色谱检测方法。方法:样品中的杂色曲霉毒素经正己烷提取后,经硅胶柱固相萃取去除脂肪等杂质,运用高效液相色谱法测定,色谱柱为Nova-Pak C18柱,以甲醇-水(70:30,V/V)为流动相,流速0.7mL/min,检测波长为246nm进行检测。结果:该方法在0.08～4.00μg/mL范围内线性良好(R2=0.9996),平均回收率为86.59%,相对标准偏差(RSD)为4.7%,最低检出量为0.017μg/kg。结论:本方法简便、快速、准确,可用于小麦中杂色曲霉毒素的测定。     

我国大陆地区食品中柄曲霉素和黄曲霉毒素B1的污染调查

为了解我国食品中黄曲霉毒素B1（Aflatoxin B1,AFB1）和柄曲霉素（Sterigmatocystin,STC）污染情况,采集自我国大陆地区1137份的食品样品以及室温储存1-2年的米份样品315份,采用高效液相色谱-串联质谱方法分析其中AFB1和STC的含量。检测结果显示食品中AFB1检出率范围为0%-40%,谷物类和谷物基加工品检出率分别为0.2%和7.8%;坚果检出率为8.7%,其中有两份样品中AFB1含量超标,啤酒中AFB1的检出率为0%。STC检出率为12.9%,平均含量为0.39 μg/kg,谷物类、谷物基加工品、坚果和啤酒中检出率分别为2.6%,28.3%,4.3%和0%。相比于所采集的超市和农贸市场样品,室温储存1-2年的米粉样品中AFB1和STC的阳性率均较高,分别为4.4%和84.8%,平均含量为0.84和2.38 μg/kg。     

响应面试验优化QuEChERS法提取鸡蛋中杂色曲霉毒素工艺及方法学验证

使用乙腈溶液对鸡蛋中杂色曲霉毒素进行提取,后加入无水Na_2SO_4、NaCl和无水CH_3COONa进行盐析,取出上层乙腈后加入C_(18)吸附剂和无水Na2SO4进行净化浓缩后上机检测。采用Plackett-Burman试验、单因素试验和响应面法优化,最大限度地提高杂色曲霉毒素的提取率。使用基质匹配曲线外标法定量,所有阳性样品均使用免疫亲和柱法复测。结果表明,杂色曲霉毒素在0.125~1 000 ng/mL质量浓度范围内线性良好,相关系数达0.999 6,检出限为0.1μg/kg,定量限为0.5μg/kg。在空白鸡蛋基质中进行三水平加标实验,测得提取率在86.8%~90.4%范围内,日间重复性在1.5%~6.2%范围内。最终,将建立的方法用于45份样品检测,其中10份鸡蛋样品检测结果呈阳性,含量为0.5~3 608μg/kg。     

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.     

Effects of Onion (Allium cepa L.) and Garlic (Allium sativum L.) Essential Oils on the Aspergillus versicolor Growth and Sterigmatocystin Production

Abstract: In the present study the effects of individual and combined essential oils (EOs) extracted from onion (Allium
cepa L.) bulb and garlic (Allium sativum L.) clove on the growth of Aspergillus versicolor and sterigmatocystin (STC) production were investigated. The EOs obtained by hydrodistillation were analyzed by GC/MS. Twenty one compounds were identified in onion EO. The major components were: dimethyl‐trisulfide (16.64%), methyl‐propyl‐trisulfide (14.21%), dietil‐1,2,4‐tritiolan (3R,5S‐, 3S,5S‐ and 3R,5R‐ isomers) (13.71%), methyl‐(1‐propenyl)‐disulfide (13.14%), and methyl‐(1‐propenyl)‐trisulfide (13.02%). The major components of garlic EO were diallyl‐trisulfide (33.55%), and diallyl‐disulfide (28.05%). The mycelial growth and the STC production were recorded after 7, 14, and 21 d of the A. versicolor growth in Yeast extract sucrose (YES) broth containing different EOs concentrations. Compared to the garlic EO, the onion EO showed a stronger inhibitory effect on the A. versicolor mycelial growth and STC production. After a 21‐d incubation of fungi 0.05 and 0.11 μg/mL of onion EO and 0.11 μg/mL of garlic EO completely inhibited the A. versicolor mycelial growth and mycotoxins biosynthesis. The combination of EOs of onion (75%) and garlic (25%) had a synergistic effect on growth inhibition of A. versicolor and STC production. Practical Application: A substitution of synthetic preservatives with natural antimicrobial compounds in food safety to control fungal contamination and mycotoxin production.     

Aflatoxin B1 and sterigmatocystin in wheat and wheat products from supermarkets in China

Wheat is an important cereal but it is often contaminated with mycotoxins. The natural occurrence of aflatoxin B₁ (AFB₁) and sterigmatocystin (STC) was determined in 178 food samples (32 wheat samples and 146 wheat products) purchased from Chinese supermarkets. The methodology was validated, the wheat and wheat products samples were treated with a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). From these samples 18.8% of wheat and 8.2% of cracker samples were contaminated with AFB₁. Mean levels were 0.06 µg/kg and 0.05µg/kg, respectively. There was no AFB₁ contamination in white bread or whole meal bread. Meanwhile 53.1% of wheat, 59.2% of crackers, 20.8% of white bread and 16% of whole meal bread samples were contaminated with STC. The mean levels were 0.07, 0.79, 0.12 and 0.12 µg/kg respectively. Although the levels were low, this demonstrates the need for more comprehensive surveys for these two mycotoxins in wheat and wheat products from China.