Analysis Of Aflatoxins Research Articles

Analysis of Aflatoxins and Ochratoxin A in Cannabis and Cannabis Products by LC-Fluorescence Detection Using Cleanup with Either Multiantibody Immunoaffinity Columns or an Automated System with In-Line Reusable Immunoaffinity Cartridges.

Evidence of fungal contamination of cannabis plants during drying has raised concerns of potential mycotoxin contamination of leaves and flowers and subsequent contamination of derived edible cannabis products. Methods are, therefore, needed for routine monitoring of cannabis to ensure consumer safety consistent with long-standing controls for mycotoxins such as aflatoxins and ochratoxin A (OTA) in foodstuffs. To generate preliminary validation data to demonstrate fitness-for-purpose of methods for aflatoxins and OTA in cannabis and cannabis products. Extraction of solid matrices with acetonitrile-water (75 + 25) and direct analysis of energy drinks after dilution. Extracts were either passed manually though an immunoaffinity column (IAC) containing antibodies to both aflatoxins and OTA or were analyzed sequentially using an automated system with in-line reusable immunoaffinity cartridges for aflatoxins or OTA. In both cases, analysis was by LC with fluorescence detection. Recoveries were in the range of 76-120% with relative SDs from 0.8 to 6.6% for aflatoxins and OTA spiked into cannabis dried leaves and flowers, hemp tea, oils, capsules, cookies, chocolate brownies, and an energy drink. The methods described in this paper are suitable for the cleanup of sample extracts of cannabis and cannabis products. Manual and automated methods with IAC cleanup have been shown to be suitable for routine control of aflatoxins and OTA in cannabis and cannabis products.

The capability of Cemba (Albizia lebbeckoides [DC.]) benth leaf extract in inhibiting Staphylococcus aureus

Cemba (Albizia lebbeckoides [DC.] Benth leaf extract contains phytochemical components namely: phenolics, flavonoids, tannins, alkaloids, glycosides, and saponins that potent to be an antibacterial agent. The study aimed to evaluate the antibacterial capability of cemba leaf extract against Staphylococcus aureus contaminating animal products frequently. Forty grams of cemba leaves were extracted with 400 mL of distilled water for 24 h. One mL of each prepared concentration of CLE (100, 105, 110, 115, 120, 125, 130, 135, and 140 mg mL−1) was cultured together with 1 mL S. aureus concentration of 1 ! 106 CFU mL−1 in MHB media, then incubated for 24 h at 37°C. Furthermore, each bacterial suspension contained in the MHB was grown on MHA media and incubated for 24 h at 37°C. The number of bacteria colonies growing was calculated for determining MIC and MBC. The time-kill test used CLE with a concentration of 1 MIC and 2 MIC. Besides, SEM was also observed to know the changes in the morphology of S. aureus cells after tested contact with 1 MIC CLE. The results showed that CLE was able to inhibit and kill S. aureus bacteria with MIC values of 120 mg mL−1 and MBC of 125 mg mL−1. Time-kill test results showed CLE concentrations of 120 mg mL−1 (1 MIC) and 240 mg mL−1 (2 MIC) were able to kill S. aureus bacteria with a contact length of 4─8 hours. The results of SEM observations indicated that CLE was able to kill S. aureus by damaging bacterial cell wallsad been tested, our method can be used for validated method for aflatoxin analysis in EBN. Further analysis of aflatoxins in edible bird nest will be reported separately.

Fast and efficient immunoaffinity column cleanup and liquid chromatography-tandem mass spectrometry method for the quantitative analysis of aflatoxins in baby food and feeds.

An ultra high performance liquid chromatography-tandem mass spectrometric method has been developed for the highly sensitive and selective determination of regulated aflatoxins. The extraction of aflatoxins from baby food matrices were performed using liquid-liquid extraction procedure followed by immunoaffinity column cleanup. The higher sensitivity for the determination of target aflatoxins was fulfilled by applying a preconcentration step with immunoaffinity columns after acetonitrile-water extraction. The enhanced selectivity was attained with the triple quadrupole mass analyzer operated in electrospray positive ionization mode. Method validation was tested in five different baby food matrices by recovery experiments. Satisfactory recoveries, between 92 and 103%, with relative standard deviations lower than 8% were achieved in all the tested matrices. The proposed method was found to be specific as no interference peaks were observed for blank samples. The limit of detection of the method was found to be in the range of 0.003-0.008ng/mL. The validated method was fruitfully applied to the screening of aflatoxins in baby foods and feeds sample retailed in local markets of Riyadh, Saudi Arabia. The obtained levels of all analyzed aflatoxins were below the regulation limits set by European Agency.

Presence of Aflatoxin M1 in Cube Cheeses Produced in Sivas Region

In this study, the presence and residue levels of aflatoxin M1 (AFM1) were investigated in traditionally produced cube cheeses in Sivas and its region. For this purpose, 90 pieces of cube cheese were used as a material. Cheese samples were collected periodically in November and December 2016 from central sales location and surrounding villages. ELISA technique was applied in aflatoxin analyses. According to the analysis results, AFM1 was detected in total of the cube cheeses. The lowest level of AFM1 was found to be 2.16 ng/kg, the highest was 53.94 ng/kg and the mean was 6.36±0.87 ng/kg. AFM1 level vas determined one cheese sample above to the limit set by European Union.

Development and Validation of a Method for Direct Analysis of Aflatoxins in Animal Feeds by Ultra-High-Performance Liquid Chromatography with Fluorescence Detection.

Aflatoxin (AF) contamination is one of the major regulatory concerns for animal feed. As feed is a complex analytical matrix, validated methods on AFs in feed are scanty. The available methods involve a derivatization step before AF analysis by high-performance liquid chromatography (HPLC) with fluorescence detection (FLD). The aim of this study was thus to develop and validate a simple and rapid method for direct analysis of AFs (AFB1, AFB2, AFG1, AFG2) in a range of animal feed matrices. Feed samples were extracted with 80% methanol, followed by dilution with water and immmunoaffinity column cleanup. AFs were estimated using an ultra-high performance liquid chromatography (UHPLC) instrument. Use of a large volume flow cell in FLD allowed direct analysis of all AFs with high sensitivity. The method was thoroughly validated in a range of feed matrices. This sample preparation workflow minimized co-extractives, along with matrix interferences. In pigeon pea husk feed, the method provided a limit of quantification (LOQ) of 0.5 ng/g for each AF with recoveries of AF- B1, B2, G1, and G2 as 71.5, 75.6, 82.4, and 78.2%, respectively. The precision (relative standard deviation, RSD) was below 5%. A similar method performance was also recorded in other matrices, including wheat bran feed and poultry feed. The optimized method is suitable for regulatory testing because it is simple, robust, cost-effective, and high throughput in nature, with high sensitivity and selectivity. Our workflow has provided a straightforward method for the analysis of AFs in a wide range of animal feed matrices with high sensitivity, selectivity, throughput, and cost-effectiveness. The method allowed a direct analysis of AFs by UHPLC-FLD without a step of derivatization.

Risk Estimation of Hepatocellular Carcinoma due to Exposure to Aflatoxins in Maize from Yogyakarta, Indonesia

Background: Besides their mutagenic, carcinogenic, and teratogenic effects, Aflatoxins (AFs) also act as the main contributor to hepatocellular carcinoma (HCC) which is known as the most common primary liver cancer worldwide. The main aim of this study was risk estimation of HCC due to exposure to aflatoxins in maize from Yogyakarta, Indonesia. Methods: As a model, maize samples were taken from Yogyakarta province, Indonesia. The present research was conducted by risk assessment approach which includes hazard identification, hazard characterization, exposure assessment, and risk characterization. The aflatoxin analysis was performed using High Performance Liquid Chromatography method and the secondary data was taken from the province report. Results: The mean total AF in raw material, dried maize chips, and fried chips were 46.58, 17.58, and 13.24 ppb, respectively. The raw material clearly had higher level of all AF types. The mean of contamination of total AF in raw material (46.58 ppb) exceeded the standard level (20 ppb), while the other products were not more than standard level. The yearly maximum exposure to AFB1 ranged from 85.07 to 92.80 ng/kg body weight per day. The estimation of HCC cases ranged from no case to 43 cases per year. Conclusion: Preventive hygienic efforts are needed to reduce AF contamination and risk of HCC in maize consumed in this region of Indonesia.

Colorimetric aggregation assay based on array of gold and silver nanoparticles for simultaneous analysis of aflatoxins, ochratoxin and zearalenone by using chemometric analysis and paper based analytical devices.

A paper based sensor array ispresented to discriminate and determine five mycotoxins classified into three categories, namely aflatoxins, ochratoxins and zearalenone. The gold and silver nanoparticles, synthesized by three different reducing or capping agents, were employed as sensing elements of thefabricated device. These nanoparticles were poured onto hydrophilic circular zones embedded on the hydrophobic substrate. The response of the assay is dependent on the aggregation of nanoparticles for interaction with mycotoxins. Due to aggregation, the gold and silver nanoparticles changed to purple and brown, respectively. Color changes provide unique colorimetric signatures conducive to recognizing the type of mycotoxin, identifying its chemical structure, and finding the fungi that produce it. The discrimination ability of the assay was investigated by both supervised (linear discriminate analysis) and unsupervised (principle component analysis and hierarchical cluster analysis) pattern recognition methods. The assay was applied to the point of need determination of aflatoxin B1, aflatoxin G1, aflatoxin M1, ochratoxin A and zearalenone with a detection limit of 2.7, 7.3, 2.1, 3.3 and 7.0ng.mL-1, respectively. The fabricated device has highpotential of simultaneously determining the mycotoxins in pistachio, wheat, coffee and milk with the help of partial least square method. The root mean square errors for prediction of PLS model were 5.7, 5.2, 1.5, 7.2 and 2.9 for aflatoxin B1, aflatoxin G1, aflatoxin M1, ochratoxin A and zearalenone, respectively. Graphical abstractSchematic representation of paper based colorimetric sensor array based on gold and silver nanoparticles for both qualitative and quantitative analysis of aflatoxins, ochratoxin and zearalenone.

A Liquid Chromatographic Method for Rapid and Sensitive Analysis of Aflatoxins in Laboratory Fungal Cultures.

Culture methods supplemented with high-performance liquid chromatography (HPLC) technique provide a rapid and simple tool for detecting levels of aflatoxins (AFs) produced by fungi. This study presents a robust method for simultaneous quantification of aflatoxin (AF) B1, B2, G1, and G2 levels in several fungal cultivation states: submerged shake culture, liquid slant culture, and solid-state culture. The recovery of the method was evaluated by spiking a mixture of AFs at several concentrations to the test medium. The applicability of the method was evaluated by using aflatoxigenic and non-aflatoxigenic Aspergilli. A HPLC coupled with the diode array (DAD) and fluorescence (FLD) detectors was used to determine the presence and amounts of AFs. Both detectors showed high sensitivity in detecting spiked AFs or AFs produced in situ by toxigenic fungi. Our methods showed 76%–88% recovery from medium spiked with 2.5, 10, 50, 100, and 500 ng/mL AFs. The limit of quantification (LOQ) for AFs were 2.5 to 5.0 ng/mL with DAD and 0.025 to 2.5 ng/mL with FLD. In this work, we described in detail a protocol, which can be considered the foremost and only verified method, to extract, detect, and quantify AFs employing both aflatoxigenic and non-toxigenic Aspergilli.

Evaluating the protective effect of edible coatings on lipid oxidation, fatty acid composition, aflatoxins levels of roasted peanut kernels

Lipid oxidation is a problem associated with roasted peanuts which occurs during storage time and contributes to development of rancidity. Fungi can grow upon peanuts and produce carcinogenic byproducts such as aflatoxins. This study investigated the effect of different concentration of edible coatings including β-glucan and chitosan on shelf-life parameters of peanuts. Lipid oxidation was evaluated by peroxide value (PV), thiobarbituric acid (TBA) and anisidine value (AV). The induction time (ti), hardness and viscosity of samples were measured using rancimat instrument, texture analyzer and rheometer, respectively. The dilution plating method was used for fungal counts and analysis of aflatoxins was performed by High-Performance Liquid Chromatography (HPLC). Lipid oxidation of samples was significantly affected by all formulations of coatings (p < 0.05). After four months of storage, β-glucan/chitosan coated (coating with both β-glucan and chitosan in coating formulation) peanuts significantly showed the least lipid oxidation values. The oil stability of peanuts was significantly affected by all formulations of coatings (p < 0.05). After four months storage, the highest level of polyunsaturated fatty acids (PUFAs) was observed in β-glucan/chitosan coated sample. Interestingly, there was a direct relationship between the viscosity of coating solutions and the hardness of peanuts. The chitosan and β-glucan/chitosan coated samples showed the highest viscosity and hardness during storage time (p < 0.05). In terms of the moisture content, fungal counts and mean total aflatoxins levels, the coated samples with 1% chitosan showed the least levels during storage time in comparison with other samples. Consequently, coating the peanuts with natural solutions can be an alternative and useful method to peanut storage.

Oil Characterization and Aflatoxin Profile of Peanut Kernel Subjected to Gamma Irradiation

Peanuts are nutritious foods, however, following harvest and storage, these nuts are prone to mycotoxin contamination. Gamma irradiation is an effective technique in postharvest pest control to kill insects and inhibit mycotoxin biosynthesis. Thus, this study aimed to investigate the effect of doses of gamma ray on oil properties and mycotoxin profile of raw peanut seeds. Seeds were exposure to gamma radiation at 10 and 25 kGy and stored at ambient temperature for 6 months compared to non-treated seeds before storage. Color, hardness, oil content, total sugar, total protein content, peroxide value (PV), malonaldehyde (MDA) and aflatoxin analysis were assessed. According to this finding, no significant differences of color, hardness, oil content, PV, MDA were found among treatments. Aflatoxin inhibition and total sugars of treated gamma irradiation peanuts at 10 kGy were higher than treated peanuts at 25 kGy.

Assessment of Quality of &amp;lt;i&amp;gt;Artemisia afra&amp;lt;/i&amp;gt; Powder Used as Antimalarial in Tanzania

The quality of herbal medicine can be affected by environmental conditions where by the medicinal plants are grown or collected, the area where they are dried and processed, storage conditions, transport conditions and manufacturing processes at the point of production. The study aimed to determine the quality of heavy metals, aflatoxins and microbial contaminants of Artemisia afra leaves powder used as herbal medicine processed at the Institute of Traditional Medicine of the Muhimbili University of Health and Allied Sciences (MUHAS). Artemisia afra leaves powder was obtained from The Institute of Traditional Medicine (ITM) in Tanzania where it is processed and packed as Fivisia. Microbial contaminants were analyzed by using plate count method for moulds and Shigella spp. while Most Probable Number (MPN) method used for determination of E. coli; Heavy metals were analyzed using; Inductively Couple Plasma – Mass Spectrometry (ICP-MS) and aflatoxin analysis was done using High Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS). The data were tabulated, expressed in mean±S. D and presented in graphs and compared to WHO guidelines. The quantity of molds was between 1.1× 103 – 1.2× 103 CFU/g which is below the legal limit according to WHO of maximum of 105 CFU/g, none of the samples were contaminated with E. coli or Shigellas sp. Levels of heavy metals were within the permissible limit for consumed herbal product according to WHO standard guidelines; Chromium 1.69 ± 0.08 ppm, Lead 0.22 ± 0.01, Cadmium 0.08 ± 0.01, Mercury 0.15± 0.08 and Arsenic 0.04 ± 0.02. All samples were found below the detection limit for aflatoxin B1, B2, G1 and G2. The Artemisia afra leaves powder processed and packed as Fivisia at the Institute of Traditional Medicine; Muhimbili University of Health and Allied Sciences (MUHAS) is safe for human consumption based on the quality parameters that have been studied.

Macroscopic, microscopic, and preliminary analytical evaluation and quality assessment of the root of Samarakhadyam (Byttneria herbacea Roxb.): An extrapharmacopoeial drug of Ayurveda

BACKGROUND: Byttneria herbacea Roxb., an extrapharmacopoeial plant of Ayurveda, locally known as Samarakhai by tribal people of Odisha, belongs to the family Sterculiaceae. The roots of B. herbacea is traditionally claimed to be used in the management of wounds, fractures, swellings, gynecological disorders, diarrhea, cuts, ulcers, and others. Although the plant is used traditionally, for its pharmacognostical characteristics, no proper scientific evaluation has been reported. AIMS: To establish and standardize the root of the plant for its microscopical and physicochemical characteristics along with different qualitative tests and to assess heavy metals, aflatoxins, and insecticide and pesticide residue. MATERIALS AND METHODS: After proper authentication, the roots were exposed to macroscopy, microscopy and physicochemical, qualitative and high-performance thin-layer chromatography study as per the Ayurvedic Pharmacopoeia of India. Heavy metal analysis, aflatoxin analysis, and insecticide and pesticide residue analysis of the root were carried out following the standard methods. RESULTS: Microscopic study, through transverse section of root shows outer multilayered elongated compactly arranged cork cells, multiseriate medullary rays embedded with brown content, starch grains and prismatic crystals, centrally located vascular bundle consist of xylem and phloem. Physicochemical parameters showed that water-soluble extractive value (11.995%) was more than that of methanol-soluble extractive (5.936%). Chromatography study exhibited 8 peaks at 254 nm and 4 peaks at 366 nm. Heavy metals and aflatoxins B2, G1, and G2 were found in the prescribed limit, whereas aflatoxin B1 was above the limit of quantification. Insecticide and pesticide residues were not detected in the sample. CONCLUSION: Typical microscopical characteristics are multiseriate medullary rays, tannin contents, and prismatic crystals. Heavy metals and aflatoxins B2, G1, and G2 were found below the limit of quantification. The findings of the study may be helpful to identify, standardize, and for quality assessment of root of B. herbacea.

Investıgatıon of Natural Mycoflora and Aflatoxin Formation in Hazelnuts and Products

In this study, natural mycoflora of 30 raw and 50 roasted hazelnut, 20 hazelnut paste and 50 inner membrane samples and their total aflatoxin contents were determined. In mycological isolations, 1.8-2.56% of Aspergillus flavus and 42.7-65.44% of A. niger were determined in the raw hazelnut samples. A. flavus (2.2-12.2%) and A. niger (33.3-74.5%) were also detected in roasted hazelnut, while the percentages of these microorganisms in hazelnut paste samples were 0-13.1% and 43.5-100.0%, respectively. The ratio of A. flavus and A. niger in inner membranes was found to be 2.6-16.2% and 44.6-89.4%, respectively. Aflatoxin analysis showed that the levels of aflatoxin were 2.11–10.03 ppb in raw hazelnut, 0.1–4.04 ppb in roasted hazelnut, 0.2-6.02 ppb in hazelnut paste samples and 0.7-38.2 ppb in inner membrane samples. While only one of the raw hazelnut, roasted hazelnut and hazelnut paste samples had toxin above the legal limit, 100% of the inner membrane samples showed different levels of aflatoxin contamination. Since there is no limitation in the Turkish Food Codex on hazelnut inner membrane, the amount of aflatoxin, which is higher than 10 ppb in 25 of the samples, was considered to be high contamination. Kruskal Wallis and Mann Whitney U analyses were used for statistical evaluation of the samples. There was a significant difference in aflatoxin formation and moisture content between the samples in different groups (p &amp;lt;0.05).

Comparison of the Aflatoxin levels in Fish Feeds from Rainbow Trout Farms Localized at Different Regions (Adana-Ağrı, TURKEY)

Aflatoxins levels in different fish feeds obtained from two different rainbow trout (Oncorhynchus mykiss) farms located in Adana and Ağrı regions were determined between May and July 2017. During the experiment period, ''a drought status'' was reported according to the Standardized Precipitation Index of Turkey by Turkish State Meteorological Service. According to precipitation index records, while Adana was reported as slightly humid, Ağrı was slightly dry in the period between May and July 2017. The aflatoxin analyses of fish feed samples was carried out in the laboratories of the Ministry of Food, Agriculture and Livestock in Adana, Turkey. The aflatoxin levels of the samples were resolved by liquid-solid extraction, immune-affinity pillar clean-up using a HPLC-FD (High Performance Liquid Chromatography with Fluorescence Detection). The detection limits of aflatoxin were 0.50, 0.23, 0.73, 0.20 ppb for AFB1, AFB2, AFG1, AFG2, respectively. The results showed that, aflatoxin levels of fish feeds were below the detection limits in all samples.Aflatoxins levels in different fish feeds obtained from two different rainbow trout (Oncorhynchus mykiss) farms located in Adana and Ağrı regions were determined between May and July 2017. During the experiment period, ''a drought status'' was reported according to the Standardized Precipitation Index of Turkey by Turkish State Meteorological Service. According to precipitation index records, while Adana was reported as slightly humid, Ağrı was slightly dry in the period between May and July 2017. The aflatoxin analyses of fish feed samples was carried out in the laboratories of the Ministry of Food, Agriculture and Livestock in Adana, Turkey. The aflatoxin levels of the samples were resolved by liquid-solid extraction, immune-affinity pillar clean-up using a HPLC-FD (High Performance Liquid Chromatography with Fluorescence Detection). The detection limits of aflatoxin were 0.50, 0.23, 0.73, 0.20 ppb for AFB1, AFB2, AFG1, AFG2, respectively. The results showed that, aflatoxin levels of fish feeds were below the detection limits in all samples.

Interference of mycotoxin binders with ELISA, HPLC and LC-MS/MS analysis of aflatoxins in maize and maize gluten

ABSTRACTThe aim of this study was to investigate the impact of mycotoxin binders on the determination of aflatoxins in maize and maize gluten using various analytical methods, including ELISA, HPLC and LC-MS/MS. Three types of commercially available mycotoxin binders, yeast cell wall, mineral, and a mixture of mineral and bacterium, were investigated at inclusion levels of 0.1%, 0.2% and 0.4%. The binders were added to maize and maize gluten contaminated with aflatoxins at concentrations between 6.9 and 26.7 μg kg−1. The samples were analysed and the values were compared with corresponding controls (samples without binders) using ANOVA. The yeast cell wall binder had no significant effect (p=0.05) on the concentration of aflatoxins measured in either maize or maize gluten at any of the three inclusion levels, regardless of which analytical method was used. The mineral binder and the mixed mineral and bacterium binder had no significant effect (p=0.05) on the measured aflatoxin concentrations in either maize or maize gluten at any of the three inclusion levels when analysis was conducted using LC-MS/MS. Inclusion of these binders resulted in significant lower (p<0.01) detection of aflatoxins in both maize and maize gluten when analysis was conducted using ELISA; the effect was dose-dependent. They also resulted in significant lower detection of aflatoxins in maize extracted by methanol/water (70/30 v/v) (p<0.0001) and in maize gluten extracted by acetonitrile/water (80/20 v/v) (p<0.05) when analysis was conducted using HPLC. However, neither the mineral binder nor the mixed mineral and bacterium binder had significant effects (p=0.05) on aflatoxin concentrations measured in maize using HPLC, when extracted by acetonitrile/water (80/20 v/v). The study demonstrated that mycotoxin binders could result in underestimation of the levels of aflatoxin contamination, depending on the nature of the binder, the extraction solvent used in the analytical method, and the composition of tested sample.

Analysis of aflatoxins in foods retailed in Saudi Arabia using immunoaffinity column cleanup and high-performance liquid chromatography-fluorescence detection

A liquid–liquid extraction based high performance liquid chromatography-fluorescence method has been proposed for the quantitation of naturally producing aflatoxins in nuts and nut based products. Aflatoxins extraction from nuts and nut products was involved methanol – water extraction, immunoaffinity column cleanup followed by post column derivatization technique. The gel contents of monoclonal antibody of the column are very specific to the toxins of interest, which makes the extraction experiment rapid, simple, highly specific and sensitive. Additionally, the improve concentration of toxins from complex nuts and nut product matrices helps to reduced chromatography interference and lower limit of detection. The proposed method was authenticated to evaluate the performance in terms of linearity of the calibration, limit of detection, recovery, run-to-run (repeatability) and day-to-day precision (reproducibility). Good quality parameters with LOD between 0.003 and 0.007 ppb, recovery from 89 to 98%, linearity in the range of 0.02 to 100 ppb (r2 > 0.989) and precisions with RSDs were achieved below 4.5% at concentration level of 1.0 and 30.0 ppb. The developed method was effectively used to the analysis of aflatoxins (AFB1, AFB2, AFG1, and AFG2) in twenty nuts and nut products and were found up to 120.1 ng/mL AFB1 and 11.2 ppb AFB2 in few of the samples.

Analysis and health risk assessment of aflatoxin B_1 residue in Ziziphi Spinosae Semen

This study aimed to analyze the residues of aflatoxin B_1( AFB_1) in Ziziphi Spinosae Semen from different producing areas and to assess the health risk of aflatoxin B_1 residue based on the obtained data. A total of 72 samples of Ziziphi Spinosae Semen from different areas were detected by IAC-HPLC-FLD. Based on the data of AFB_1 pollution,a probabilistic assessment model with Monte Carlo simulation was developed. Then,the risk assessment of AFB_1 exposure by Ziziphi Spinosae Semen intake was carried out by MOE( margin of exposure). The results showed that 32 out of 72 of samples( 44. 4%) were found to be contaminated with AFB_1,and the average and maximum concentration of AFB_1 in samples was 5. 42 μg·kg~(-1) and 55. 09 μg·kg~(-1),respectively. After health risk assessment,the average and 97. 5%( 90% confidence interval) exposure level of daily exposure of AFB_1 by Ziziphi Spinosae Semen intake were 0. 008 6( 0. 008 1-0. 009 2) and 0. 057 3( 0. 053 2-0. 061 4) μg·kg~(-1)·d~(-1),respectively. The results showed common use of Ziziphi Spinosae Semen had low level of risk associated with AFB_1. However,the high consumption of Ziziphi Spinosae Semen showed a higher risk than common intake,requiring attention. This study laid a foundation for clinical safe prescription of Ziziphi Spinosae Semen.

A Simple Strategy Based on Deep Eutectic Solvent for Determination of Aflatoxins in Rice Samples

The liquid-phase extraction combined with newly green extraction solvent named deep eutectic solvent has been widely used. In this work, a simple and fast analytical method based on deep eutectic solvent (DES) was developed for simultaneous determination of aflatoxin G1, B1, G2, and B2 in rice samples. With simple liquid-phase extraction, aflatoxins were quickly enriched into a tetramethylammonium chloride-malonic acid (n/n, 1:2) DES, accompanied with the enhancement of fluorescence intensity of aflatoxins without any derivatization process. Various parameters were optimized to achieve the best extraction efficiency. Under the optimal conditions, satisfactory linearity ranges (0.2–20 μg/kg for aflatoxin G1, 0.1–20 μg/kg for aflatoxin B1, 0.06–6 μg/kg for aflatoxin G2, and 0.03–6 μg/kg for aflatoxin B2), low LODs (0.06 μg/kg for aflatoxin G1, 0.03 μg/kg for aflatoxin B1, 0.02 μg/kg for aflatoxin G2, and 0.01 μg/kg for aflatoxin B2), good precision (RSD < 5.52%), and recoveries (78.93–113.64%) were obtained. These results met the determination requirements of aflatoxins, which demonstrated that DES could be used as an efficient extractant for aflatoxins analysis in rice samples.

Simultaneous Direct Analysis of Aflatoxins and Ochratoxin A in Cereals and Their Processed Products by Ultra-High Performance Liquid Chromatography with Fluorescence Detection

Abstract Background: Mycotoxins such as aflatoxins (AFs) and ochratoxin A (OTA) can pose severe health hazards because of their toxicity. Given a wide range of food matrices susceptible to fungal infections and possible cooccurrence of mycotoxins at different concentrations, validated multimycotoxin and multimatrix methods are strongly warranted. Objective: The aim of this research was to develop a simple and fast ultra-high performance LC (UHPLC) fluorescence detection (FLD)–based method to simultaneously determine AFs (B1, G1, B2, and G2) and OTA and, furthermore, to carry out single-laboratory validation in a range of cereals and processed product matrices. Methods: The sample preparation involved homogenization and extraction with methanol–water (80 + 20). For cleanup, an aliquot (3 mL) was diluted with phosphate-buffered saline, loaded on an immunoaffinity column (AFLAOCHRA PREP®), and eluted with methanol (1 mL). The cleaned extract was diluted with 0.2% acetic acid (at a 1:1 ratio) before injection into an ultra-high performance liquid chromatograph. To perform simultaneous analysis of AFs and OTA, the FLD program was developed by switching the excitation wavelength in a single chromatographic run. Results: The method provided LOQs of 0.25 and 1 ng/g for AFs and OTA, respectively, without involving any derivatization. In rice, the recoveries of AFs ranged from 84 to 106%, whereas OTA had a recovery above 72%, with the repeatability relative SDs &amp;lt;12% for both analytes. The method was successfully applied to a range of naturally contaminated market samples. Conclusions: The method is suitable for regulatory testing because of its significant time and cost effectiveness and sensitivity in compliance with the regulatory maximum levels. Highlights: The study achieves high-throughput analysis of AFs and OTA in raw and processed cereals using simultaneous extraction, cleanup, and UHPLC-FLD. Method sensitivity complies with the regulatory maximum levels. Single-laboratory validation results meet analytical QC requirements.

Determination of Aflatoxin B1 and B2 in Vegetable Oils Using Fe3O4/rGO Magnetic Solid Phase Extraction Coupled with High-Performance Liquid Chromatography Fluorescence with Post-Column Photochemical Derivatization.

In this study, magnetic graphene nanocomposite Fe3O4/rGO was synthesized by facile one-pot solvothermal method. The nanocomposite was successfully used as magnetic solid phase extraction (MSPE) adsorbents for the determination of aflatoxins in edible vegetable oils through the π–π stacking interactions. MSPE parameters including the amount of adsorbents, extraction and desorption time, washing conditions, and the type and volume of desorption solvent were optimized. Under optimal conditions, good linear relationships were achieved. Limits of detection of this method were as low as 0.02 µg/kg and 0.01 µg/kg for aflatoxin B1 and B2, respectively. Finally, the magnetic graphene nanocomposite was successfully applied to aflatoxin analysis in vegetable oils. The results indicated that the recoveries of the B-group aflatoxins ranged from 80.4% to 106.0%, whereas the relative standard deviations (RSDs) were less than 8.1%. Owing to the simplicity, rapidity and efficiency, Fe3O4/rGO magnetic solid phase extraction coupled with high-performance liquid chromatography fluorescence with post-column photochemical derivatization (Fe3O4/rGO MSPE-HPLC-PCD-FLD) is a promising analytical method for routine and accurate determination of aflatoxins in lipid matrices.