Collaborative Study of Methods for the Determination and Chemical Confirmation of Aflatoxin M1 in Dairy Products

1974 ◽  
Vol 57 (4) ◽  
pp. 852-857
Author(s):  
Robert D Stubblefield ◽  
Gail M Shannon
Keyword(s):  
Dairy Products ◽  
Collaborative Study ◽  
Test Methods ◽  
Aflatoxin M1 ◽  
Powdered Milk ◽  
Blue Cheese ◽  
Chromatography Analysis ◽  
Liquid Milk ◽  
Layer Chromatography ◽  
Derivatives Of

Abstract An international collaborative study involving 19 collaborators was conducted to test methods for the determination and chemical confirmation of aflatoxin M1 in dairy products. For the quantitative method, collaborators assayed samples of liquid and powdered milk, cheese, and butter containing low levels of M1. Statistical results indicated that sensitivity and precision of this method were comparable to other AOAC methods for aflatoxin M1. Impurities were present in blue cheese extracts that tended to interfere with thin layer chromatography. Analysis of liquid milk samples from different areas revealed that some milk extracts may require column chromatography. For the chemical confirmatory method, collaborators prepared acetate and hemiacetal derivatives of M1 in extracts of liquid milk and colby cheese. A sensitivity limit of 30 ng M1 was apparent for the method, and most collaborators easily identified the derivatives. As a result of this collaboration, both methods have been adopted as official first action methods.

Determination and Confirmation of Identity of Aflatoxin M1 in Dairy Products: Collaborative Study

1980 ◽  
Vol 63 (4) ◽  
pp. 907-921
Author(s):  
Robert D Stubblefield ◽  
Hans P Van Egmond ◽  
Walter E Paulsch ◽  
Pieter L Schuller ◽  
◽  
...  
Keyword(s):  
Dairy Products ◽  
Rapid Determination ◽  
Collaborative Study ◽  
Test Methods ◽  
Aflatoxin M1 ◽  
Powdered Milk ◽  
Limit Of Determination ◽  
Sample Extraction ◽  
Study Results ◽  
Derivatives Of

Abstract An international collaborative study involving 23 collaborators was conducted to test methods, improved over previous methods with respect to speed and solvent use, for the rapid determination and thin layer chromatographic (TLC) confirmation of aflatoxin M1 identity in dairy products. For the quantitative method, collaborators assayed samples of Couda and cheddar cheeses, powdered milk, and butter containing levels of M1 near the anticipated limit of determination. Statistical analysis of the study results indicated that the lower limit of determination and precision of this method were comparable to these parameters of methods previously approved for analysis for aflatoxin M1. A few collaborators found that M1 eluted early from cleanup columns with cheese and butter samples and that emulsions formed during powdered milk sample extraction. The reasons for these problems have been determined and remedies are provided. For the TLC confirmation of identity method, collaborators prepared trifluoroacetic acid derivatives of M1 on the plates after 2-dimensional development. Concentrations as low as 0.3 ng/g cheese and 1.0 ng/g powdered milk were determined in this study. As a result of this study, both methods have been adopted as official first action methods by the AOAC and as reference methods by IUPAC.

Aflatoxin M1 in Milk: Evaluation of Methods

1973 ◽  
Vol 56 (5) ◽  
pp. 1106-1110 ◽  
Author(s):  
Robert D Stubblefield ◽  
Gail M Shannon ◽  
Odette L Shotwell
Keyword(s):  
Thin Layer ◽  
Milk Protein ◽  
Aflatoxin M1 ◽  
Acetate Solution ◽  
Powdered Milk ◽  
Methanol Solutions ◽  
Acetone Water ◽  
Liquid Milk ◽  
Time Required ◽  
Layer Chromatography

Abstract Six published methods for the determination of aflatoxin M1 in liquid and powdered milk were compared because a quantitative assay sensitive to 0.1 μg/L was needed for routine analysis. Each method was tested with both spiked and naturally contaminated samples at levels of 0.1, 0.5, and 1 μg/L or 1, 5, and 10 μg/kg; recoveries of M1 were determined. Data revealed that 2 methods, one for liquid milk and one for powdered milk, had the desired sensitivity and recoveries. In the liquid milk method, M1 is extracted and milk protein is precipitated simultaneously with methanol-water (4+1); in the powdered milk method, M1 is extracted with acetone-water (70+30) and milk protein is then precipitated with a lead acetate solution. Both methods remove fats from the aqueous acetone or methanol solutions with hexane before partition of M1 into chloroform. Aflatoxin M1 is determined by thin layer chromatography of the chloroform extracts and either visual or densitometric measurement of mycotoxin on thin layer plates. Modifications were made to simplify the methods and to reduce the time required to complete the assays.

TYRAMINE, HISTAMINE, AND TRYPTAMINE CONTENT OF CHEESE

1974 ◽  
Vol 37 (7) ◽  
pp. 377-381 ◽  
Author(s):  
M. N. Voigt ◽  
R. R. Eitenmiller ◽  
P. E. Koehler ◽  
M. K. Hamdy
Keyword(s):  
Cheddar Cheese ◽  
The United States ◽  
Quantitative Information ◽  
Biologically Active ◽  
Blue Cheese ◽  
Physiological Importance ◽  
Fluorescence Measurements ◽  
Soft Cheese ◽  
Layer Chromatography ◽  
Derivatives Of

Because of the increasing knowledge of the physiological importance of biologically active amines in man and the importance of the presence of these amines in cheese, this study was done to obtain quantitative information for tyramine, tryptamine, and histamine in cheese available in the United States. The tyramine, histamine, and tryptamine contents of 156 samples of cheese purchased at retail stores were quantitated by thin-layer chromatography and fluorescence measurements of NBD-chloride derivatives of the amines. Tyramine was found in 81 of 85 Cheddar cheese samples examined. Extra-sharp, sharp, and medium Cheddar cheese samples contained average tyramine values of 0.27, 0.21, and 0.24 mg/g, respectively. Average tyramine contents were lower in mild and processed Cheddar (0.09 and 0.11 mg/g, respectively). The highest Cheddar cheese tyramine content was 0.7 mg/g. Tyramine was consistently found in all cheeses except in unripened soft cheese (Cottage). Histamine concentrations varied from nondetectable amounts to 2.6 mg/g in a Sap-Sago cheese sample. Twenty-four Cheddar cheese samples contained histamine with the highest amount being 1.3 mg/g. A domestic Blue cheese contained 2.3 mg/g. Tryptamine was uniformly low or completely absent in the Cheddar cheese samples. The highest tryptamine concentration (1.1 mg/g) was detected in a Blue cheese.

Rapid Thin Layer Chromatographic Determination of Aflatoxin M1 in Powdered Milk

1985 ◽  
Vol 68 (5) ◽  
pp. 952-954
Author(s):  
Maria Luisa Serralheiro ◽  
Maria Lurdes Quinta
Keyword(s):  
Aqueous Solution ◽  
Carbon Tetrachloride ◽  
Thin Layer ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Methanol Solution ◽  
Aflatoxin M1 ◽  
Powdered Milk ◽  
Layer Chromatography

Abstract A method has been developed for the detection of aflatoxin Mi in milk. The toxin is extracted with chloroform, the extract is evaporated, and the residue is partitioned between carbon tetrachloride and an aqueous saline-methanol solution. The toxin is once again extracted with chloroform from the methanol solution and analyzed by thin layer chromatography. The limit of detection of Mi in powdered milk is 0.5 μg/ kg; recoveries of added Mj are about 83%. The limit of detection can be improved to 0.3 μg/kg if the plate is sprayed with an aqueous solution of H2S04 after development.

scholarly journals Immunoaffinity Column Cleanup with Liquid Chromatography for Determination of Aflatoxin M1 in Liquid Milk: Collaborative Study

2001 ◽  
Vol 84 (2) ◽  
pp. 437-443 ◽  
Author(s):  
Sylviane Dragacci ◽  
Frederic Grosso ◽  
John Gilbert ◽  
M Agnedal ◽  
L Hyndrick ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Aflatoxin M1 ◽  
Immunoaffinity Column ◽  
Precision Data ◽  
Relative Standard ◽  
Liquid Milk

Abstract A collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatographic method for determination of aflatoxin M1 in milk at proposed European regulatory limits. The test portion of liquid milk was centrifuged, filtered, and applied to an immunoaffinity column. The column was washed with water, and aflatoxin was eluted with pure acetonitrile. Aflatoxin M1 was separated by reversed-phase liquid chromatography (LC) with fluorescence detection. Frozen liquid milk samples both naturally contaminated with aflatoxin M1 and blank samples for spiking, were sent to 12 collaborators in 12 different European countries. Test portions of samples were spiked at 0.05 ng aflatoxin M1 per mL. After removal of 2 noncompliant sets of results, the mean recovery of aflatoxin M1 was 74%. Based on results for spiked samples (blind pairs at 1 level) and naturally contaminated samples (blind pairs at 3 levels) the relative standard deviation for repeatability (RSDr) ranged from 8 to 18%. The relative standard deviation for reproducibility (RSDR) ranged from 21 to 31%. The method showed acceptable within- and between-laboratory precision data for liquid milk, as evidenced by HORRAT values at the low level of aflatoxin M1 contamination.

Determination of Anatoxin M, in Milk and Milk Products Contaminated at Low Levels

1987 ◽  
Vol 70 (3) ◽  
pp. 470-472
Author(s):  
Lucas Dominguez ◽  
Jose L Blanco ◽  
Esperanza Gomez-Lucia ◽  
Elias F Rodriguez ◽  
Guillermo Suarez
Keyword(s):  
Detection Limit ◽  
Dairy Products ◽  
Aflatoxin Production ◽  
Aflatoxin M1 ◽  
Production Studies ◽  
Low Detection Limit ◽  
Low Levels ◽  
Layer Chromatography ◽  
Milk And Dairy Products

Abstract A new method is described for the determination of aflatoxin M, in milk and dairy products by thin layer chromatography. The main characteristic is the extraction system using an alkaline solution. Lipids are removed by centrifuging at low temperatures, and the aflatoxins are then extracted with CHC13. The method has 2 options: Technique II (detection limit 0.02 ppb) requires cleanup on a chromatographic column; this is not necessary in Technique I (detection limit 0.1 ppb). The recovery rate in both techniques is over 92.8% in milk and yoghurt. This method may also be used for other aflatoxins. Because of the advantages of the method, Technique II is recommended for aflatoxin M1, control in milk, where a low detection limit is necessary. Technique I is proposed for experimental aflatoxin production studies in dairy products, which require analysis of a large number of samples but which do not require a very low detection limit.

scholarly journals Evaluation and Assessment of Aflatoxin M1 in Milk and Milk Products in Yemen Using High-Performance Liquid Chromatography

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Safwan Murshed
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Dairy Products ◽  
High Performance ◽  
Dairy Product ◽  
Aflatoxin M1 ◽  
Fluorescence Detector ◽  
Milk Products ◽  
Acceptable Range ◽  
Liquid Milk

Aflatoxin M1 is one of the major fungal contaminants found in dairy products around the globe. The objective of this study was to investigate the incidence and occurrence of aflatoxin M1 (AFM1) in samples of milk and milk products in Yemen. The tested dairy product samples were collected from different sources for aflatoxin M1 (AFM1) in Yemen. A total of 250 local and imported samples consisting of 38 liquid milk, 60 powder milk, 62 yogurt, and 90 cheese samples which are marketed throughout Yemen were tested by using high-performance liquid chromatography (HPLC) along with a fluorescence detector and immunoaffinity column purification for detection of AFM1. High levels of AFM1 were detected in preserved milk (77.24%), ranging from 0.021 μg/L to 5.95 μg/L. On the other hand, AFM1 was detected in 66.66% and 68.42% in powdered milk and liquid milk samples, respectively. Among dairy products, 87.09% of yogurt and 81.39% of cheese samples were found contaminated with AFM1. The AMF1 values were higher than the acceptable range for humans set by the European Union. So, we concluded that dairy products used in Yemen showed an AFM1 content beyond the acceptable range, and this is a major factor for causing health-related complications including cancer. In the present study, we reported for the first time the presence of mycotoxins especially AFM1 in dairy products used in Yemen.

The prevalence of aflatoxin M1 (AFM1) in conventional and industrial dairy products (yogurt, cheese, kashk and dough) of Iran: a systematic review and meta-analysis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pouran Makhdoumi ◽  
Hooshyar Hossini ◽  
Reza Mohammadi ◽  
Mojtaba Limoee
Keyword(s):  
Dairy Products ◽  
Meta Analysis ◽  
Dairy Product ◽  
Rapid Test ◽  
Aflatoxin Contamination ◽  
Aflatoxin M1 ◽  
Toxic Metabolite ◽  
Sample Type ◽  
Production Type ◽  
Layer Chromatography

Abstract Aflatoxin is a toxic metabolite produced mainly by Aspergillus spp. which may occur in dairy products because of biotransformation. In this work, a systematic and meta-analysis approach has been considered on the topic of aflatoxin M1 (AFM1) content in dairy Iranian products. Based on the literature review, AFM1 was the most common aflatoxin contamination in dairy product. Additionally, studies revealed that higher levels of AFM1 were produced during cold seasons includes winter and autumn. Although, immunochemical technique (ELISA) was the frequent and rapid test, thin-layer chromatography (TLC) and chromatographic methods (HPLC) were commonly used as confirmative techniques to determine the level of aflatoxin. Meta-analyzing of the results showed that AFM1 can be found in the dairy products with overall prevalence percentage of 63.53 (95% confidence interval [CI]: 56.28–70.78) and 54.05 (95% CI: 43.09–65.02) based on the sample type and production process, respectively. The higher prevalence percentage of AFM1 of 73.96 (95% CI: 60.27–87.66) and 69.91 (95% CI: 62.00–78.83) was found in yoghurt and industrial production type of samples, respectively. In general, 17.8% of cheese, 14% of yogurt, 12.63% of kashk, and 2.1% of doogh contained AFM1 in concentrations exceeding the permitted level of standards. Totally, results showed that 88.89% of dairy products were contaminated by AFM1 exceeding from standard limits.

SKRINING FITOKIMIA DAN ANALISIS KROMATOGRAFI LAPIS TIPIS EKSTRAK KULIT PISANG KEPOK

2021 ◽  
Vol 10 (1) ◽  
pp. 54-61
Author(s):  
Isna Mulyani ◽  
Rizki Nisfi Ramdhini ◽  
Syaikhul Aziz
Keyword(s):  
Thin Layer ◽  
Ethanol Extract ◽  
Mutagenic Effect ◽  
Test Methods ◽  
Banana Peel ◽  
Phytochemical Screening ◽  
Chromatography Analysis ◽  
Chromatographic Profile ◽  
Qualitative Test ◽  
Layer Chromatography

Kepok banana peel is an organic waste that has potential to be reused. Several studies proofed that banana peels have antioxidant activity, antimicrobial, inhibit the formation of cholesterol crystals and gallstones, diuretic effect, and mutagenic effect. This study aims to identify secondary metabolites contained in kepok banana peels using qualitative test methods (phytochemical screening) and thin layer chromatography analysis. The results of the phytochemical screening of kepok banana peel indicated the presence of alkaloids, monoterpenes/sesquiterpenes, phenols/tannins, saponins,and quinones. Thin layer chromatographic profile of ethanol extract showed the presence of flavonoid, phenol, and quinone compounds.Keywords: Phytochemical, chromatography, banana peel

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