Effect of monogastric and ruminant gastrointestinal conditions on in vitro aflatoxin B1 adsorption ability by a montmorillonite

The main objective of this study was to evaluate the interference of environment components on the in vitro evaluation of aflatoxin B₁ adsorption capacity of sodium bentonite under simulated gastrointestinal conditions of monogastric and ruminant animals. Sodium bentonite showed a high aflatoxin B₁ affinity with all of the assays. Langmuir or sigmoid isotherms were found in different assays. Both the affinities and the surface excesses at monolayer saturation were affected by the buffer components. The specific influence of ions in each buffer solution was investigated. A significant decrease in the surface excess at monolayer saturation was observed under ionic strength control. A change in the isotherm shape from sigmoidal to Langmuir was observed with the increase in the sodium chloride concentration. This was attributed to the decrease in the importance of lateral interaction between adsorbed toxin molecules compared with surface-molecules interactions under a high salt coverage. The presence of rumen fluid components in the adsorption environment decreased the aflatoxin B₁ maximum adsorption capacity of sodium bentonite. Despite the high affinity of this adsorbent to capture aflatoxin B₁, different substances present in the environment could affect the adsorption capacity, at least at low toxin concentrations that mimic chronic exposure. The environment of the gastrointestinal tract, in either monogastric or ruminant animals, affect in vivo aflatoxin B₁ adsorption by sodium bentonite and should be taken into account when an in vitro performance evaluation is done.     

Negligible effects of tryptophan on the aflatoxin adsorption of sodium bentonite

The main objective of this study was to determine if the competitive adsorption of tryptophan (Trp) and aflatoxin B₁ (AFB₁) could potentially affect the ability of a sodium bentonite (NaB) to prevent aflatoxicosis in monogastric animals. The adsorption of Trp and AFB₁ on this adsorbent is fast and could be operating on the same time-scale making competition feasible. In vitro competitive adsorption experiments under simulated gastrointestinal conditions were performed. A high affinity of the clay for Trp and NaB was observed. The effect of an excess of KCl to mimic the ionic strength of the physiological conditions were also investigated. A six-times decrease in the Trp surface excess at saturation was observed. A similar behaviour was previously found for AFB₁ adsorption. Taking into account the amount of Trp adsorbed by the clay and the usual adsorbent supplementation level in diets, a decrease in Trp bioavailability is not expected to occur. Tryptophan adsorption isotherms on NaB were ‘S’-shaped and were adjusted by the Frumkin–Fowler–Guggenheim model. The reversibility of the adsorption processes was investigated in order to check a potential decrease in the ability of NaB to protect birds against chronic aflatoxicoses. Adsorption processes were completely reversible for Trp, while almost irreversible for AFB₁. In spite of the high affinity of the NaB for Trp, probably due to the reversible character of Trp adsorption, no changes in the AFB₁ adsorption isotherm were observed when an excess of the amino acid was added to the adsorption medium. As a consequence of the preferential and irreversible AFB₁ adsorption and the reversible weak binding of Trp to the NaB, no changes in the aflatoxin sorption ability of the clay are expected to occur in the gastrointestinal tract of birds.     

酶联免疫吸附法测定花生油中黄曲霉毒素B1 不确定度的评定

目的对采用ELISA方法测定花生油中黄曲霉毒素B1含量的不确定度进行分析,找出影响不确定度的因素,为评价其测定方法和检测结果的可靠性提供依据。方法根据JJF 1059.1-2012《测量不确定度评定与表示》的规定,对测定过程中标准曲线拟合、重复测量、样品的稀释、样品的称量、回收率等引入的不确定度分量进行评定。结果测定结果合成不确定度为0.45μg/kg,扩展不确定度为0.90μg/kg,花生油中黄曲霉毒素B1含量测定结果为(16.54±0.90)μg/kg(k=2)。结论测定结果不确定度主要由标准曲线拟合所引入,所建立的不确定度评定方法可用于ELISA方法测定花生油中黄曲霉毒素B1含量结果的判断。     

Efficacy of Solis, NovasilPlus, and MTB-100 to reduce aflatoxin M1 levels in milk of early to mid lactation dairy cows fed aflatoxin B1

An experiment was conducted to determine the efficacy of 3 adsorbents, Solis (SO; Novus International Inc.), NovasilPlus (NOV; Engelhard Corp.), and MTB-100 (MTB; Alltech), in reducing aflatoxin (AF) M₁ concentrations in milk of dairy cows fed an AF-contaminated diet. Twelve early to mid lactation dairy cows averaging 163 d in milk were used in a 4 × 4 Latin square design with 3 replications. Cows were blocked by parity, body weight, and milk production and were provided ad libitum access to feed and water. Within each replicate, cows were randomly assigned to the 4 dietary treatments for 4 consecutive 7-d periods. Dietary treatments included AF [112 μg of AFB₁/kg of diet dry matter (DM)]; AF + 0.56% SO; AF + 0.56% NOV; and AF + 0.56% MTB. Milk samples were collected on d 6 and 7 of each of the experimental periods. Feed intake, milk production, milk fat percentage, milk protein percentage, and linear somatic cell scores were not affected by dietary treatments and averaged 22.20 kg/d of DM, 33.87 kg/d, 3.78%, 2.95%, and 1.60, respectively, across all treatments. Transfer rates of AF from feed to milk averaged 2.65, 1.48, 1.42, and 2.52% for cows fed AF, AF + SO, AF + NOV, and AF + MTB, respectively. Daily AFM₁ excretion in milk averaged 66, 37, 35, and 63 μg/d for cows fed AF, AF + SO, AF + NOV, and AF + MTB, respectively. The addition of SO and NOV to the AF diet resulted in a significant reduction in milk AFM₁ concentrations (SO, 45%; NOV, 48%) and AFM₁ excretion (SO, 44%; NOV, 46%). In contrast, MTB was not effective in reducing milk AFM₁ concentrations (4%), AFM₁ excretion (5%), or AF transfer from feed to milk (2.52%). Results indicated that SO and NOV at 0.56% of the diet were effective in reducing milk AFM₁ concentrations in cows consuming a total mixed ration containing 112 μg of AFB₁/kg of diet DM.     

2015年山东部分地区食用植物油中黄曲霉毒素B1和玉米赤霉烯酮污染状况调查

摘 要：目的 了解山东省部分地区食用植物油中黄曲霉毒素B1和玉米赤霉烯酮的污染状况,为食品安全监督管理提供科学依据。方法 在山东省部分市/县采集食用植物油,256份8类植物油,散装油206份,定型包装油59份,其中包括花生油105份、大豆油78份、玉米胚芽油9份、香油46份、调和油10份以及其他食用油17份,酶联免疫吸附法检测AFB1和ZEN的含量,并根据食品安全国家标准食品中真菌毒素限量分析植物油中的AFB1和ZEN污染状况。结果 256份样品中,AFB1和ZEN检出率分别为44.5%、72.1%,超标率分别为7.2%、6.0%,中位数分别为0.0、4.9 μg/kg。定型包装和散装油中,AFB1超标率分别为0.0%、9.2%,差异有统计学意义（?2=4.55,P＜0.05）,中位数分别为0.6 μg/kg、0.0 μg/kg;ZEN超标率分别为10.2%、4.9%,中位数分别为5.1 μg/kg、4.8 μg/kg。各城市间AFB1总体来说差异有统计学意义（?2=32.31,P＜0.05）;ZEN在不同地区间差异无统计学意义（?2=16.06,P＞0.05）。花生油和大豆油中AFB1超标率分别为16.2%、2.6%,差异有统计学意义（?2=8.93,P＜0.05）,其他种类植物油中未发现超标;花生油、大豆油、玉米胚芽油、香油、调和油ZEN的超标率分别为1%、1.3%、100.0%、8.7%、20.0%,各类食用油中ZEN超标率差异有统计学意义（P＜0.05）。结论 山东部分地区食用植物油中AFB1和ZEN污染严重,其中以散装油污染最为严重。花生油中AFB1、玉米油中ZEN污染严重,建议相关部门加强市场散装油的监管。     

In vivo toxicity assessment of aflatoxin B1-contaminated corn after ozone degradation

Corn is an important food and feedstuff in China and worldwide. The problems caused by aflatoxin B₁-contaminated corn (ACC) are of great concern. Our previous studies have demonstrated that ozone can effectively degrade AFB₁ in corn, prompting us to investigate the in vivo toxicity of treated ACC. In this study, 35 Kunming mice were used to assess the in vivo toxicity of ozone treated ACC. Results indicated that compared to mice fed with basal feedstuff (provided by the Shanghai SLAC Laboratory), those fed with ACC have significantly decreased mean weight as well as total protein (TP), albumin (ALB), and globulin (GLB) contents (p < 0.05). On the other hand, the liver and kidney/body weight ratio as well as the serum alanine transaminase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels significantly increased (p < 0.05). Obvious histopathological changes were found in the liver and kidney. When mice were fed with the ozone-treated ACC, no significant differences were observed in the mean weight, the liver and kidney/body weight ratio and in the major serum indexes ALT, TP, ALB, and GLB (p > 0.05). However, AST and ALP significantly increased (p < 0.05), and slight histopathological changes were found in liver tissues. This study indicated that ACC may lead to significant changes in various physiological characteristics and biochemical indexes in liver and kidney tissues, but ozone treatment of ACC could significantly reduce these changes.     

Aflatoxin M1 in raw milk and aflatoxin B1 in feed from household cows in Singida,Tanzania

Aflatoxin M₁ (AFM₁) contamination in raw milk from household cows fed with sunflower seedcakes or sunflower-based seedcake feeds was determined in 37 milk samples collected randomly from different locations in Singida region, Tanzania. Aflatoxin B₁ (AFB₁) contamination in sunflower-based seedcake feed was determined in 20 feed samples collected from the same household dairy farmers. The samples were analysed by RP-HPLC using fluorescent detection after immunoaffinity column clean-up. Recoveries were 88.0% and 94.5%, while the limits of detection (LOD) were 0.026 ng mL^?1 and 0.364 ng g^?1 for AFM₁ and AFB₁, respectively. Of the analysed cow’s milk samples, 83.8% (31/37) contained AFM₁, with levels ranging from LOD to 2.007 ng mL^?1, exceeding both the European Commission (EC) and Tanzania Food and Drug Authority (TFDA) limit of 0.05 ng mL^?1. Of the contaminated samples, 16.1% exceeded the Codex Alimentarius limit of 0.5 ng mL^?1. AFB₁ was present in 65% (13/20) of the feed samples with levels ranging from LOD to 20.47 ng g^?1, 61.53% exceeding the TFDA and EC maximum limits of 5 ng g^?1 for complete dairy animal feed. The observed AFM₁ and AFB₁ contamination necessitates the need to raise awareness to dairy farmers in Tanzania to safeguard the health of the end-users.     

Short communication: Investigation of aflatoxin M1 levels in infant follow-on milks and infant formulas sold in the markets of Ankara,Turkey

Aflatoxins are fungal toxins known to be carcinogenic and are classified as food contaminants. This study was performed to investigate aflatoxin (AF) M₁ levels in baby foods sold in Ankara (Turkey) and to evaluate the obtained results according to the Turkish Food Codex (TFC). For this purpose, a total of 84 baby food samples (50 follow-on milks and 34 infant formulas) were obtained from different markets in Ankara and the presence of AFM₁ in the samples was analyzed by ELISA. In 32 (38.1%) of 84 infant food samples, the presence of AFM₁ was detected in concentrations ranging between 0.0055 and 0.0201 µg/kg. The mean level (±standard error) of AFM₁ was found to be 0.0089 ± 0.0006 µg/kg in positive infant follow-on milks. Aflatoxin M₁ was detected in only 1 infant formula sample (2.94%) at a concentration of 0.0061 µg/kg. The extrapolated levels of AFB₁ contamination in feedstuffs were calculated based on levels of AFM₁ in baby food samples. The data estimating AFB₁ contamination in dairy cattle feedstuff indicate that contamination may range from 0.3410 to 1.2580 µg/kg, with the mean level (±standard error) being 0.5499 ± 0.0385 µg/kg, which is lower than the level set by the TFC and European Union regulations (5 µg/kg). According to the obtained results, the levels of AFM₁ in analyzed samples were within the allowed limit (0.025 µg/kg) set in the TFC. Low levels of AFM₁ in infant follow-on milks and infant formula samples obtained during the study do not pose a health risk to infants.     

间接ELISA检测不同贮存条件下花生中黄曲霉毒素B1

建立了一种利用间接ELISA检测花生中黄曲霉毒素B1的方法,同时考察了平衡相对湿度及贮存时间对花生中黄曲霉毒素B1(AFB1)含量的影响。结果表明:该方法的重现性好,AFB1回收率在95.20%~97.75%之间,线性范围为0.049~0.971μg/kg,最低检出限为0.029μg/kg;花生中AFB1的含量随平衡相对湿度的升高而增加,随贮存时间延长,其含量也不断增加。但平衡相对湿度低于57.6%时,即使贮存90 d,花生中的AFB1含量仍低于国家食品安全标准限量(20μg/kg)。     

微生物法针对毒性位点降解黄曲霉毒素B1的研究进展

文章主要探究了黄曲霉毒素B₁(AFB₁)的毒性位点及毒性机理,并对比了微生物法破坏AFB₁毒性位点从而降解AFB₁的优势。重点综述了微生物法中的脱毒酶法对AFB₁的降解机制。同时,对脱毒酶法联合其他方法的复合应用进行展望。     

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。     

Saccharomyces cerevisiae strains and the reduction of Aspergillus parasiticus growth and aflatoxin B1 production at different interacting environmental conditions,in vitro

The effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B₁ binding ability and beneficial properties, against Aspergillus parasiticus under different interacting environmental conditions was evaluated. Studies concerning the lag phase, growth rate and aflatoxin B₁ production were carried out in vitro under different regimes of a _w (0.95 and 0.99), pH (4 and 6), temperature (25 and 37°C), and oxygen availability (normal and reduced). Both yeast strains showed great antagonistic activity at pH 4, decreasing growth rate compared with the control. The RC008 strain showed the greatest inhibitory activity at all assayed conditions. A. parasiticus produced large amounts of AFB₁ in vitro. A significant decrease of AFB₁ levels in comparison with the control were observed with yeast interaction. Differences between control and treatment values ranged from 130 to 5400?ng?ml^?1. S. cerevisiae RC008 and RC016 could be considered as effective agents in reducing growth and AFB₁ production at different interacting environmental conditions, related to that found in stored feedstuff. The importance of the present work lies in the search for live strains with both probiotic and biocontrol properties able to prolong the safe storage of feedstuff and exert beneficial properties after animal consumption and which could be included in a novel product for animal feed.     

Simultaneous determination of aflatoxin B1 and M1 in milk,fresh milk and milk powder by LC-MS/MS utilising online turbulent flow chromatography

A novel, fully automated method based on dual-column switching using online turbulent flow chromatography followed by LC-MS/MS was developed for the determination of aflatoxin B₁ and M₁ in milk, fresh milk and milk powder samples. After ultrasound-assisted extraction, samples were directly injected into the chromatographic system and the analytes were concentrated on the clean-up loading column. Through purge switch, analytes were transferred to the analytical column for subsequent detection by mass spectrometry. Different types of TurboFlow^TM columns, transfer flow rates and transfer times were optimised. Method limits of detection obtained for AFB₁ and AFM₁ were 0.05 μg kg^–1, and limits of quantification were 0.1 μg kg^–1. Recoveries of aflatoxin B₁ and M₁ were in range of 81.1–102.1% for all samples. Matrix effects of aflatoxin B₁ and M₁ were in range of 63.1–94.3%. The developed method was successfully used for the analysis of aflatoxin B₁ and M₁ in real samples.     

广东省常见发酵茶中黄曲霉毒素B1污染现状及暴露评估

目的了解广东省市售包括黑茶、红茶、乌龙茶等发酵茶中黄曲霉毒素B1(AFB1)的污染含量水平,并评估其饮用健康风险。方法按照简单随机抽样方法确定样品量,在广东省4个片区选取9个地市的超市商店、批发市场、茶叶行等市售环节以及网店,分别采集黑茶、红茶、乌龙茶等发酵茶类样品共260份,按GB 5009.22—2016《食品安全国家标准食品中黄曲霉毒素B族和G族的测定》第一法同位素稀释-液相色谱-串联质谱法测定其中的AFB1含量。运用暴露限值(MOE)法和数学模型法,结合2012年广东省居民营养与健康状况调查数据、AFB_1浸出率数据,评估人群从饮用茶叶摄入AFB1的膳食暴露量情况。结果 260份发酵茶类样品中AFB1的总体检出率为1.15%(3/260),检出值范围为0.26~0.56μg/kg。3份检出AFB_1的样品均为普洱茶熟茶样品。3种发酵茶类别间的检出率差异无统计学意义(P0.05)。代入发酵茶中AFB_1的含量平均值计算,广东省总人群、广东省茶叶消费人群经茶叶摄入AFB_1的平均膳食暴露量分别为0.000 352、0.000 981 ng/kg BW;代入AFB1含量最大值计算的膳食暴露量为0.005 73、0.016 0 ng/kg BW。MOE值均10 000,按欧洲食品安全局推荐的MOE结果判定依据,表明广东省居民经茶叶摄入的AFB1对健康造成危害的风险低。以广东省人群乙肝表面抗原(HBsAg)阳性率为11.1%计算,广东省人群由于茶叶AFB1的膳食暴露引发肝癌的风险为0.000 010 9~0.000 674例/10万人,表明目前茶叶中的AFB_1对广东省居民产生的健康风险低。结论广东省市售发酵茶中AFB_1的检出率低、检出值低,对广东省总人群和茶叶消费人群的平均膳食暴露风险低,具有较高的饮用安全性。     

Versicolorin A is a potential indicator of aflatoxin contamination in the granary-stored corn

The objective of this study was to evaluate the feasibility of the predictive monitoring of aflatoxin B₁ (AFB₁) under granary conditions, since mycotoxin contamination of the stored grain represents an important issue. Using the storage test, we investigated the relationship between versicolorin A (Ver A, an intermediate in AFB₁ biosynthesis) levels and the levels of aflatoxigenic fungi, and their relationship with aflatoxin production. All samples, except for one, were found to be contaminated with aflatoxigenic fungi using PCR analyses, while their AFB₁ levels were not detectable before the storage test using an enzyme-linked immunosorbent assay (ELISA) method with an LOD of 2 μg/kg. Aflatoxigenic fungi levels were analysed, as well as Ver A levels prior to the accumulation of AFB₁ (Levels were ≥5 μg/kg; the permissible levels of AFB₁ in corn intended for direct consumption are <5 μg/kg (EC)). Statistical analyses demonstrated that aflatoxin levels after both actual storage and safe storage (AFB₁?5μg/kg) times are significantly correlated with the Ver A levels and the changes in Ver A levels (ΔVer A). Both high and variable Ver A levels were indicative of the vigorous metabolic activity of aflatoxigenic fungi. In contrast, steady Ver A levels showed that aflatoxin production by the fungi was not active. Monitoring Ver A levels and their changes may allow an earlier detection of harmful aflatoxin contamination in the stored grain. Additionally, the toxicity of Ver A should be further examined. The results of our study indicate that the monitoring of Ver A levels, even when the AFB₁ levels are very low, may increase the safety of grain consumption, especially considering Ver A toxicity.     

Time-resolved fluorescent immunochromatographic assay-based on three antibody labels for the simultaneous detection of aflatoxin B1 and zearalenone in Chinese herbal medicines

ABSTRACT

A time-resolved fluorescent immunochromatographic assay (TRFICA) was successfully developed for the sensitive, simultaneous, and quantitative detection of aflatoxin B₁ (AFB1) and zearalenone (ZEN) in Chinese herbal medicines. Eu-nanospheres (EuNPs) with unique optical properties increased the stability and sensitivity of the immunochromatographic assay. To obtain stable quantitative results, we applied a three-label system in which monoclonal antibodies for AFB1 and ZEN were conjugated to the EuNPs as detection probes on the test line (T line), and EuNP-labelled chicken IgY conjugates acted as the reference on the control line (C line). The fluorescence intensities of the T and C lines were recorded, and the T/C ratio was employed as the quantitative signal for the elimination of strip variation and matrix effects. The parameters that affected the TRFICA were optimised. Under optimal conditions, the established TRFICA gave good linear ranges from 0.60 μg/kg to 3.92 μg/kg for AFB1 and from 0.40 μg/kg to 1.28 μg/kg for ZEN. The limits of detection for AFB1 and ZEN were as low as 0.60 and 0.40 μg/kg, respectively, in Chinese herbal medicines Semen coicis, Rhizoma dioscoreae, and Platycodon grandiflorus, respectively. The average recoveries of the spiked samples were 73%–95% for AFB1 and 75.83%–90% for ZEN, both with a relative standard deviation of < 9.08%. The results of 15 actual samples detected by the developed TRFICA showed a satisfactory correlation with those of ultra-performance liquid chromatography tandem mass spectrometry. Therefore, the TRFICA is a simple, rapid, and sensitive approach to quantitatively detect mycotoxins in Chinese herbal medicines.     

Activated carbons as potentially useful non-nutritive additives to prevent the effect of fumonisin B1 on sodium bentonite activity against chronic aflatoxicosis

Aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) are mycotoxins that often co-occur in feedstuffs. The ingestion of AFB₁ causes aflatoxicosis in humans and animals. Sodium bentonite (NaB), a cheap non-nutritive unselective sequestering agent incorporated in animal diets, can effectively prevent aflatoxicosis. Fumonisins are responsible for equine leukoencephalomalacia and porcine pulmonary oedema, and often have subclinical toxic effects in poultries. Fumonisin B₁ and aflatoxin B₁ are both strongly adsorbed in vitro on sodium bentonite. Co-adsorption studies, carried out with a weight ratio of FB₁ to AFB₁ that mimics the natural occurrence (200:1), showed that FB₁ greatly decreases the in vitro ability of NaB to adsorb AFB₁. The ability of two activated carbons to adsorb FB₁ was also investigated. Both carbons showed high affinity for FB₁. A complex behaviour of the FB₁ adsorption isotherms with pH was observed. In vitro results suggest that under natural contamination levels of AFB₁ and FB₁, a mixture of activated carbon and sodium bentonite might be potentially useful for prevention of sub-acute aflatoxicosis.     

Natural co-occurrence of ochratoxin A,ochratoxin B and aflatoxins in Sicilian red wines

The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B₁, aflatoxin B₂, aflatoxin G₁ and aflatoxin G₂ (OTA, OTB, AFB₁, AFB₂, AFG₁, AFG₂) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l^–1, well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG₁, present in 57.9% of samples, while the other aflatoxins were rarely present. Recovery experiments were carried out on eight mycotoxin-free red wines spiked with OTA, OTB, AFB₁, AFB₂, AFG₁ and AFG₂ at two different levels. The limits of detection (LODs) in wines were 0.02 µg l^–1 for OTA, 0.04 µg l^–1 for OTB, 0.03 µg l^–1 for AFG₁, AFG₂ and AFB₂, and 0.05 µg l^–1 for AFB₁. A good correlation was found, with good performances in term of precision for the method.     

碳量子点/银复合材料用于食用油中黄曲霉毒素B1的检测

采用原位复合法制备出高效复合的碳量子点/银复合材料(CDs/Ag),研究了黄曲霉毒素B_1(AFB_1)对CDs/Ag荧光强度的影响。结果表明:AFB_1与CDs/Ag溶液相互作用后,体系的荧光强度增强,由此建立测定食用油中AFB_1的新方法。在p H 7.6的硼酸-硼砂缓冲溶液中,CDs/Ag和AFB_1在25℃反应30 min时,体系荧光强度(F)与AFB_1质量浓度(c)呈良好线性关系,线性范围为0.01~0.8μg/m L,线性方程为F=1 902c+309.3,R~2为0.998 4,检出限为7.4×10~(-3)μg/m L。采用该方法测定了食用油中AFB_1的含量,回收率为95%~106%。