Screening and Quantitation of Ochratoxin A in Corn, Peanuts, Beans, Rice, and Cassava

1985 ◽  
Vol 68 (6) ◽  
pp. 1128-1130
Author(s):  
Lucia M Valente Soares ◽  
Delia R Rodriguez-Amaya
Keyword(s):  
Ochratoxin A ◽  
Chloroform Extract ◽  
Cupric Sulfate ◽  
Corn Meal ◽  
Black Beans ◽  
Polished Rice ◽  
Yellow Corn ◽  
Coefficients Of Variation ◽  
Layer Chromatography ◽  
Different Levels

Abstract To answer the need for simple, economical, rapid methods for mycotoxins, a procedure for screening and quantitation of ochratoxin A was developed. A methanol-aqueous KC1 extraction is used, followed by cleanup with clarifying agents and partition into chloroform. Part of the chloroform extract is used for screening and the other part for quantitation by thin layer chromatography (TLC). The screening procedure takes 40 min, using a silica gel/aluminum oxide minicolumn developed for this purpose. The limits of detection are 80 and 10 |xg/ kg, respectively, for minicolumn screening and TLC quantitation. Ammonium sulfate is efficient in cleaning samples of corn and cassava; cupric sulfate is better with peanuts, beans, and rice. Tests were conducted on triplicate spiked samples of yellow corn meal, raw peanuts, dried black beans, polished rice, and cassava flour at different levels (400, 200, 80, 40, and 10 p-g/kg). Recoveries ranged from 86 to 160% and the coefficients of variation ranged from 0 to 26%.

Simultaneous Extraction and Fractionation and Thin Layer Chromatographic Determination of 14 Mycotoxins in Grains

1979 ◽  
Vol 62 (3) ◽  
pp. 573-578 ◽  
Author(s):  
Yuiko Takeda ◽  
Etsuko Isohata ◽  
Ryuji Amano ◽  
Mitsuru Uchiyama
Keyword(s):  
Thin Layer ◽  
Chromatographic Determination ◽  
Chloroform Extract ◽  
Simultaneous Extraction ◽  
Polished Rice ◽  
Rough Rice ◽  
The Individual ◽  
Layer Chromatography ◽  
Chloroform Methanol

Abstract A simple, systematic analytical method for multiple mycotoxins was developed for detecting 14 mycotoxins: aflatoxins Bl, B2, G1, and G2, sterigmatocystin, T-2 toxin, diacetoxyscirpenol, neosolaniol, fusarenon X, zearalenone, ochratoxin A, citrinin, luteoskyrin, and rugulosin. These mycotoxins were extracted with 20% H2SO4-4% KCl-acetonitrile (2+20+178), defatted with isooctane, and transferred to chloroform. The chloroform extract was cleaned up by silica gel column chromatography; the first 10 toxins were eluted with chloroform-methanol (97+3) and the remaining 4 toxins with benzene-acetone-acetic acid (75+20+5). Each fraction was analyzed by thin layer chromatography for the final determination. The method has been applied to polished rice, rough rice, corn, wheat, and peanuts as an analytical screening procedure. The detection limits in these commodities ranged from 10.0 to 800.0 μg/kg, depending on the mycotoxin, but all limits were superior to those obtained for the individual mycotoxins by using other methods.

Screening Method for the Detection of Aflatoxins in Mixed Feeds and Other Agricultural Commodities with Subsequent Confirmation and Quantitative Measurement of Aflatoxins in Positive Samples

1975 ◽  
Vol 58 (3) ◽  
pp. 500-506 ◽  
Author(s):  
Thomas R Romer
Keyword(s):  
Quantitative Measurement ◽  
Screening Method ◽  
Peanut Meal ◽  
Chloroform Extract ◽  
Agricultural Commodities ◽  
Acetone Water ◽  
Coefficients Of Variation ◽  
Aoac Method ◽  
Mixed Feeds ◽  
Layer Chromatography

Abstract The method described will detect total aflatoxins (B1, B2, G1, and G2) in mixed feeds, grains, nuts, and fruit products in samples containing as little as 5–15 μg/kg. In addition, the presence of aflatoxins in the positive samples can be confirmed and the toxins can be quantitatively measured, using the same extract as that used for the screening method. In the screening method, aflatoxins are extracted with acetone-water (85+15), and interferences are removed by adding cupric carbonate and ferric chloride gel. The aflatoxins are extracted from the aqueous phase with chloroform and the chloroform extract is washed with a basic aqueous solution. A Velasco-type minicolumn is used to further purify the extract and capture the aflatoxins in a tight band. The screening method has been successfully applied to 24 different agricultural commodities. Quantitative thin layer chromatography was also performed with extracts of each of these commodities. An average recovery of 94% B1, 108% B2, 130% Gl, and 103% G2 was obtained compared to the official final action AOAC method for cottonseed products, 26.048–26.056. Within-laboratory coefficients of variation of 10–15% were obtained for each of the aflatoxins and total aflatoxins in a sample of peanut meal naturally contaminated with 11 μg B1 + 3 μg B2 + 11 μg G1+ 5 μg G2/kg.

Improved thin-layer chromatography of disaturated phosphatidylcholine in amniotic fluid.

1981 ◽  
Vol 27 (2) ◽  
pp. 239-242 ◽  
Author(s):  
M Y Tsai ◽  
M Cain ◽  
M W Josephson
Keyword(s):  
Respiratory Distress ◽  
Thin Layer ◽  
Amniotic Fluid ◽  
Thin Layer Chromatography ◽  
Fetal Lung ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Fetal Lung Maturity ◽  
Coefficients Of Variation ◽  
Layer Chromatography ◽  
Lung Maturity

Abstract We describe an indirect test of fetal lung maturity: the quantitation of disaturated phosphatidylcholine in amniotic fluid. The lipids in samples of amniotic fluid from 172 patients were reacted with osmium tetroxide, and disaturated phosphatidylcholine was then isolated by thin-layer chromatography. Interfering substances were retained by a pre-adsorbent layer. The charred disaturated phosphatidylcholine, quantitated by densitometry, was compared to standard dipalmitoyl phosphatidylcholine. Both within-run and between-run coefficients of variation were about 10%. Blood and meconium do not interfere. Six infants developed respiratory distress when disaturated phosphatidylcholine concentrations of amniotic fluid drawn within 72 h of delivery were less than 5.5 mg/L. A concurrently determined lecithin/sphingomyelin ratio falsely predicted lung maturity in one of these. In seven other samples for which lecithin/sphingomyelin ratios suggested lung immaturity but disaturated phosphatidyl-choline predicted maturity, none of the infants developed respiratory distress. In normal pregnancies, measurement of disaturated phosphatidylcholine in amniotic fluid appears to be a better predictor of fetal lung maturity than is measurement of the lecithin/sphingomyelin ratio. Further studies are needed to determine if this analysis is a better predictor in diabetic pregnancies.

Comparison of Chemical Analysis and Bioassay as Measures of Vitamin A Value: Yellow Corn Meal

1953 ◽  
Vol 50 (1) ◽  
pp. 85-100 ◽  
Author(s):  
Elizabeth Crofts Callison ◽  
Lois F. Hallman ◽  
William F. Martin ◽  
Elsa Orent-Keiles ◽  
Emily S. Conway ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Vitamin A ◽  
Corn Meal ◽  
A Value ◽  
Yellow Corn

scholarly journals DETECTION AND INVESTIGATION OF ASPERGILLUS NIGER AND OCHRATOXIN A IN WALNUT AND PEANUT

2017 ◽  
Vol 48 (5) ◽  
Author(s):  
Khalifa & et al.
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Plant Protection ◽  
Uv Light ◽  
Wave Length ◽  
Artificial Medium ◽  
College Of Agriculture ◽  
Local Markets ◽  
Layer Chromatography ◽  
Isolation Test

This study was conducted at the Department of Plant Protection-College of Agriculture-University of Baghdad during 2015 -2016. The objective of the study is to investigate the contamination of the fungus Aspergillus niger in the seeds of peanuts and walnuts from the Iraqi local markets and the ability of these isolates to produce ochratoxin A in artificial medium. Forty samples of peanuts and walnuts were collected from local markets of the governorates of Baghdad, Erbil, Sulaymaniyah , Anbar and Dyiala for isolation test of  A. nigar. Results showed that A.niger was founded in the samples of walnuts from Erbil at percentage of 50% and 42.8% in the samples of peanuts from Baghdad ,and 40 % in peanuts from each Anbar and Dyiala, in addition to the fungus A.flavus at a rate of33.3 و 28.8 %  in the walnuts from Erbil and Baghdad respectively and 30% و28.8% in the peanuts from Anbar and Baghdad respectively. Eleven isolates of fungus A.niger was tested against its ability to produce Ochratoxin A after grown in yeast and sucrose extract media and analyzed using thin layer chromatography (TLC) under UV light wave length of 365 nanometer, two isolates were identified (K,E) out of the A.niger fungus isolated from peanuts found to be able to produce Ochratoxin A at different rates, depending on the degree of the brightness of the spots compared with standard Toxin. Then the eleven isolates were identified by morphology characters and confirm by using specific primer NIG1and NIG2, all the isolates showed to be A.niger.

Collaborative Study of a Rapid Method for Extraction of Light Filth from Corn Meal, Rye, Pumpernickel, and Buckwheat Flour

1971 ◽  
Vol 54 (4) ◽  
pp. 903-905
Author(s):  
Mary T Miller
Keyword(s):  
Rapid Method ◽  
Collaborative Study ◽  
Mineral Oil ◽  
Corn Meal ◽  
Soxhlet Extractor ◽  
Water Washing ◽  
Yellow Corn ◽  
Alcohol Water ◽  
Buckwheat Flour

Abstract A rapid method based on product defatting in a Soxhlet extractor, hydrolysis in acid-alcohol, water washing, and, finally, separation of light filth in mineral oil has been developed for the separation of light filth from white and yellow corn meal, cracked wheat, rye, pumpernickel, and buckwheat flour. Collaborative results are satisfactory for all products tested; the method has been adopted as official first action.

Screening Method for the Detection of Aflatoxins, Ochratoxin, Patulin, Sterigmatocystin, and Zearalenone in Cereals

1977 ◽  
Vol 60 (6) ◽  
pp. 1369-1371 ◽  
Author(s):  
B G Egon Josefsson ◽  
Tord E Möller
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Ochratoxin A ◽  
Screening Method ◽  
Gel Filtration ◽  
Limits Of Detection ◽  
Layer Chromatography

Abstract A screening method has been developed for the detection of aflatoxins, ochratoxin A, patulin, sterigmatocystin, and zearalenone in cereals. After extraction, the sample is cleaned up by gel filtration. The mycotoxins are separated by thin layer chromatography. The limits of detection are about 5 μg aflatoxins, 10 ochratoxin A, 50 μg patulin, 10 μg sterigmatocystin, and 35 μg zearalenone/kg.

Determination of Zearalenone in Corn: Collaborative Study

1976 ◽  
Vol 59 (3) ◽  
pp. 666-670
Author(s):  
Odette L Shotwell ◽  
Marion L Goulden ◽  
Glenn A Bennett
Keyword(s):  
Statistical Analysis ◽  
Thin Layer ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Corn Sample ◽  
Yellow Corn ◽  
Coefficients Of Variation ◽  
The Mean

Abstract Corn samples spiked at levels of 100, 300, 1000, and 2000 μg zearalenone/kg were sent to 22 collaborators for analysis by the Eppley method. All samples were yellow corn except one white corn sample spiked at 2000 μg/kg. Results from 16 collaborators were statistically analyzed. Only 4 of 16 collaborators detected zearalenone in the sample containing 100 μg/kg, but 11 detected the toxin in the sample containing 300 μg/kg. Average recoveries from all samples were 129% at 300 μg/kg, 101% at 1000 μg/kg, and 88% at 2000 μg/kg. The between-laboratory coefficients of variation were 53.0% at 300 μg/kg, 38.2% at 1000 μg/kg, and 27.0% at 2000 μg/kg. Five naturally contaminated corn samples, one in triplicate, were also provided. The mean level of zearalenone in the naturally contaminated samples ranged from 431 to 7622 μg/kg. The mean coefficient of variation for all samples was 40.5%. Two collaborators measured quantities of zearalenone on thin layer chromatographic plates densitometrically. Their results were not included in the statistical analysis, but the results indicated that densitometric measurement, given proper dilutions of solutions, could be used. The method has been adopted as official first action.

Method for the Detection and Estimation of Ochratoxin A in Some Cereal Products

1967 ◽  
Vol 50 (2) ◽  
pp. 366-370
Author(s):  
P M Scott ◽  
T B Hand
Keyword(s):  
Ochratoxin A ◽  
Aqueous Methanol ◽  
Whole Wheat Flour ◽  
Cereal Products ◽  
Whole Wheat ◽  
Sample Extract ◽  
Final Sample ◽  
Aoac Method ◽  
Layer Chromatography

Abstract A method for the detection and semiquantitative estimation of ochratoxin A in flour and other cereal products is described which can be used in conjunction with analysis of the foodstuff for aflatoxins. The sample is extracted with aqueous methanol and n-hexane and the toxin is partitioned on a Celite column, as in the AOAC method for determination of aflatoxins in peanut products. Ochratoxin A is separated by thin layer chromatography and estimated by the intensity of fluorescence compared with that of a reference standard. By this procedure, 0.01 μg ochratoxin A can be detected in 10 μl final sample extract, corresponding to a detection limit of about 25 μg/kg cereal foodstuff. The method is applicable to whole wheat flour, corn meal, barley cereal, and rice cereal. Recoveries of 80—100% of added ochratoxin A were obtained

Detection of Ochratoxin A in Barley, Using Silica Gel Minicolumns

1975 ◽  
Vol 58 (1) ◽  
pp. 156-158
Author(s):  
Benedicte Hald ◽  
Palle Krogh
Keyword(s):  
Sodium Bicarbonate ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Ochratoxin A ◽  
Silica Gel ◽  
Fluorescent Band ◽  
Contamination Levels ◽  
Simplified Procedure ◽  
Green Fluorescent ◽  
Layer Chromatography

Abstract A simplified procedure has been developed to detect ochratoxin A in cereals which can be used in the field where equipment for thin layer chromatography is not available. The procedure includes extraction of the acidified sample with chloroform, purification over sodium bicarbonate, and minicolumn chromatography. Under longwave ultraviolet light ochratoxin A appears as a blue-green fluorescent band at the lower end of the column. Contamination levels as low as 12 ppb can be detected by this method.

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