Determination of Aflatoxins B1, B2, G1, and G2 in Olive Oil, Peanut Oil, and Sesame Oil Using Immunoaffinity Column Cleanup, Postcolumn Derivatization, and Liquid Chromatography/Fluorescence Detection: Collaborative Study

2012 ◽  
Vol 95 (6) ◽  
pp. 1689-1700 ◽  
Author(s):  
Lei Bao ◽  
Chengzhu Liang ◽  
Mary W Trucksess ◽  
Yanli Xu ◽  
Ning Lv ◽  
...  
Keyword(s):  
Olive Oil ◽  
Lower Layer ◽  
Collaborative Study ◽  
Sesame Oil ◽  
Peanut Oil ◽  
Immunoaffinity Column ◽  
Fluorescence Detector ◽  
Repeatability And Reproducibility ◽  
Postcolumn Derivatization

Abstract The accuracy, repeatability, and reproducibility characteristics of a method using immunoaffinity column (IAC) cleanup with postcolumn derivatization and LC with a fluorescence detector (FLD) for determination of aflatoxins (AFs; sum of AFs B1, B2, G1, and G2) in olive oil, peanut oil, and sesame oil have been established in a collaborative study involving 15 laboratories from six countries. Blind duplicate samples of blank, spiked at levels ranging from 0.25 to 20.0 μg/kg for AF, were analyzed. A naturally contaminated peanut oil sample was also included. Test samples were extracted with methanol–water (55 + 45, v/v). After shaking and centrifuging, the lower layer was filtered, diluted with water, and filtered through glass microfiber filter paper. The filtrate was then passed through an IAC, and the toxins were eluted with methanol. The toxins were then subjected to RPLC-FLD analysis after postcolumn derivatization. Average recoveries of AFs from olive oil, peanut oil, and sesame oil ranged from 84 to 92% (at spiking levels ranging from 2.0 to 20.0 μg/kg); of AFB1 from 86 to 93% (at spiking levels ranging from 1.0 to 10.0 μg/kg); of AFB2 from 89 to 95% (at spiking levels ranging from 0.25 to 2.5 μg/kg); of AFG1 from 85 to 97% (at spiking levels ranging from 0.5 to 5.0 μg/kg); and of AFG2 from 76 to 85% (at spiking levels ranging from 0.25 to 2.5 μg/kg). RSDs for within-laboratory repeatability (RSDr) ranged from 3.4 to 10.2% for AF, from 3.5 to 10.9% for AFB1, from 3.2 to 9.5% for AFB2, from 6.5 to 14.9% for AFG1, and from 4.8 to 14.2% for AFG2. RSDs for between-laboratory reproducibility (RSDR) ranged from 6.1 to 14.5% for AF, from 7.5 to 15.4% for AFB1, from 7.1 to 14.6% for AFB2, from 10.8 to 18.1% for AFG1, and from 7.6 to 23.7% for AFG2. Horwitz ratio values were ≤2 for the analytes in the three matrixes.

scholarly journals Determination of Aflatoxins B1, B2, G1, and G2 in Olive Oil, Peanut Oil, and Sesame Oil

2010 ◽  
Vol 93 (3) ◽  
pp. 936-942 ◽  
Author(s):  
Lei Bao ◽  
Mary W Trucksess ◽  
Kevin D White
Keyword(s):  
Olive Oil ◽  
Edible Oils ◽  
Lower Layer ◽  
Multiple Reaction Monitoring ◽  
Animal Health ◽  
Sesame Oil ◽  
Peanut Oil ◽  
Immunoaffinity Column ◽  
Accuracy And Repeatability

Abstract Edible oils are consumed directly, and used as ingredients in food, soaps, and skin products. However, oils such as olive oil, peanut oil, and sesame oil could be contaminated with aflatoxins, which are detrimental to human and animal health. A method using immunoaffinity column cleanup with RPLC separation and fluorescence detection (FLD) for determination of aflatoxins (AF) B1, B2, G1, and G2 in olive oil, peanut oil, and sesame oil was developed and validated. Test samples were extracted with methanolwater (55 + 45, v/v). After shaking and centrifuging, the lower layer was filtered, diluted with water, and filtered through glass microfiber filter paper. The filtrate was then passed through an immunoaffinity column, and the toxins were eluted with methanol. The toxins were then subjected to RPLC/FLD analysis after postcolumn UV photochemical derivatization. The accuracy and repeatability characteristics of the method were determined. Recoveries of AFB1 spiked at levels from 1.0 to 10.0 g/kg in olive oil, peanut oil, and sesame oil ranged from 82.9 to 98.6. RSDs ranged from 0.6 to 8.9. HorRat values were <0.2 for all of the matrixes tested. Recoveries of AF spiked at levels from 2.0 to 20.0 g/kg ranged from 87.7 to 102.2. RSDs ranged from 1.3 to 12.6. HorRat values were <0.4 for all of the matrixes tested. LC/MS/MS with multiple-reaction monitoring was used to confirm the identities of aflatoxins in a naturally contaminated peanut oil.

scholarly journals Determination of Fumonisins B1 and B2 in Corn and Corn Flakes by Liquid Chromatography with Immunoaffinity Column Cleanup: Collaborative Study

2001 ◽  
Vol 84 (6) ◽  
pp. 1828-1838 ◽  
Author(s):  
Angelo Visconti ◽  
Michele Solfrizzo ◽  
Annalisa De Girolamo ◽  
H Bresch ◽  
P Burdaspal ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Immunoaffinity Column ◽  
Relative Standard ◽  
Repeatability And Reproducibility ◽  
Double Extraction ◽  
Standard Deviations ◽  
Corn Flakes ◽  
Liquid Chromatographic ◽  
Fumonisins B1 And B2

Abstract A liquid chromatographic (LC) method for the determination of fumonisins B1 (FB1) and B2 (FB2) in corn and corn flakes was collaboratively studied by 23 laboratories, which analyzed 5 blind duplicate pairs of each matrix to establish the accuracy, repeatability, and reproducibility characteristics of the method. Fumonisin levels in the corn ranged from <0.05 (blank) to 1.41 μg/g for FB1 and from <0.05 to 0.56 μg/g for FB2, whereas in the corn flakes they ranged from <0.05 to 1.05 μg/g for FB1 and from <0.05 to 0.46 μg/g for FB2. The method involved double extraction with acetonitrile–methanol–water (25 + 25 + 50), cleanup through an immunoaffinity column, and LC determination of the fumonisins after derivatization with o-phthaldialdehyde. Relative standard deviations for the within-laboratory repeatability (RSDr) of the corn analyses ranged from 19 to 24% for FB1 and from 19 to 27% for FB2; for the corn flakes analyses, RSDr ranged from 9 to 21% for FB1 and from 8 to 22% for FB2. Relative standard deviations for the between-laboratories reproducibility (RSDR) of the corn analyses ranged from 22 to 28% for FB1 and from 22 to 30% for the FB2; for corn flakes analyses, RSDR ranged from 27 to 32% for FB1 and from 26 to 35% for FB2. Mean recoveries of FB1 and FB2 from corn spiked with FB1 at 0.80 μg/g and with FB2 at 0.40 μg/g were 76 and 72%, respectively; for corn flakes spiked at the same levels recoveries were 110 and 97% for FB1 and FB2, respectively. HORRAT ratios for the analyses of corn ranged from 1.44 to 1.53 for FB1 and from 0.96 to 1.48 for FB2, whereas for corn flakes they ranged from 1.60 to 1.82 for FB1 and from 1.39 to 1.68 for FB2.

Determination of Ochratoxin A in Capsicum spp. (Paprika and Chili) by Immunoaffinity Column Cleanup and Liquid Chromatography: Collaborative Study

2014 ◽  
Vol 97 (3) ◽  
pp. 876-883 ◽  
Author(s):  
Zoltan Kunsagi ◽  
Joerg Stroka ◽  
E Abilleira ◽  
P Bastijns ◽  
M Berger ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Collaborative Study ◽  
Immunoaffinity Column ◽  
Fluorescence Detector ◽  
International Union ◽  
Eu Member States ◽  
Rp Hplc ◽  
Official Control ◽  
Capsicum Spp

Abstract A method validation study for the determination of ochratoxin A in Capsicum spp. (paprika and chili) was conducted according to the International Union of Pure and Applied Chemistry harmonized protocol. The method is based on the extraction of samples with aqueous methanol, followed by an immunoaffinity column cleanup. The determination is carried out by RP-HPLC coupled with a fluorescence detector. The study involved 21 participants representing a cross-section of research, private, and official control laboratories from 14 European Union (EU) Member States and Singapore. Mean recoveries reported ranged from 83.7 to 87.5%. The RSD for repeatability (RSDr) ranged from 1.7 to 14.3%. The RSD for reproducibility (RSDR) ranged from 9.1 to 27.5%, reflecting HorRat values from 0.4 to 1.3 according to the Horwitz function modified by Thompson. The correction for recovery of results from naturally contaminated samples further improved the reproducibility of the method. The method showed acceptable within-laboratory and between-laboratory precision for each matrix, and it conforms to requirements set by current EU legislation.

Alcohol Determination by HPLC with Postcolumn Derivatization Based on the Thiosulfate-catalyzed Reaction of Alcohols and Cerium(IV) and Fluorescence Detection of Cerium(III)

2020 ◽  
Vol 16 ◽  
Author(s):  
Ikko Mikami ◽  
Eri Shibayama ◽  
Kengo Takagi
Keyword(s):  
Detection Limit ◽  
Fluorescence Detection ◽  
Reaction Rate ◽  
Detection Method ◽  
Fluorescence Detector ◽  
Reaction Solution ◽  
Optimum Detection ◽  
Postcolumn Derivatization ◽  
Sensitive Method

Background: Determination of a reducing substance based on the reaction between Ce(IV) and a reducing substance and fluorescence detection of Ce(III) generated has been reported as a selective and sensitive method. However, this method could not be applied to the determination of alcohol due to the low reaction rate of alcohol and Ce(IV). Objective: We found that thiosulfate catalytically enhanced reaction of alcohols (such as, methanol, ethanol, and propanol) and Ce(IV). Utilizing this effect, we developed a new method for the determination of alcohols. Results: In the presence of thiosulfate, an increase in fluorescence intensity was detected by injecting alcohol at concentrations of several millimolar, whereas it was not observed even at the concentration of 10% v/v (2 M for ethanol) in the absence of thiosulfate. The optimum detection conditions were determined to be 4.0 mM Ce(IV) sulfate and 0.50 mM thiosulfate, and the detection limit (S/N = 3) of ethanol under these conditions was 1 mM. In the calibration curves, changes in the slope were observed when the alcohol concentrations were approximately 10–25 mM. Using a thiosulfate solution containing ethanol as the reaction solution, a calibration curve without any change in slope was obtained, although the concentration of ethanol at the detection limit increased. The alcohols in the liquor and fuel were successfully analyzed using the proposed detection method as a postcolumn reaction. Conclusion: This new alcohol detection method using a versatile fluorescence detector can be applied to the postcolumn reaction of HPLC omitting need of time-consuming pretreatment processes.

Convection Oven Determination of Loss of Mass on Drying of Quick Frozen French Fried Potatoes: Collaborative Study

1984 ◽  
Vol 67 (3) ◽  
pp. 635-636 ◽  
Author(s):  
David O Biltcliffe ◽  
Hillary J Judd ◽  
Roger Wood ◽  
◽  
A C Bushnell ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Frozen Foods ◽  
Codex Alimentarius Commission ◽  
Convection Oven ◽  
Economic Commission ◽  
Two Samples ◽  
Repeatability And Reproducibility ◽  
Loss Of Mass ◽  
Fried Potatoes

Abstract A collaborative study was carried out on one of the methods submitted to the Joint Economic Commission for Europe (ECE)/Codex Alimentarius Commission Group of Experts on the Standardization of Quick Frozen Foods for the determination of moisture in quick frozen french (fried potatoes. The method was based on the determination of loss of mass of the sample on drying in a convection oven 16 h at 103±2°C. Two samples of uncooked quick frozen french fried potatoes and 2 samples of oven quick frozen french fried potatoes were analyzed by 14 and 13 laboratories, respectively. The method is simple and was found to be analytically satisfactory with repeatability and reproducibility values of 0.21 and 2.00 g/100 g french fried potatoes, and 0.29 and 3.00 g/100 g oven french fried potatoes, respectively. The method was adopted by the Group of Experts in preference to other proposed procedures for this determination. The method has been adopted official first action by AOAC.

scholarly journals Determination of Ochratoxin A in Wine and Beer by Immunoaffinity Column Cleanup and Liquid Chromatographic Analysis with Fluorometric Detection: Collaborative Study

2001 ◽  
Vol 84 (6) ◽  
pp. 1818-1827 ◽  
Author(s):  
Angelo Visconti ◽  
Michelangelo Pascale ◽  
Gianluca Centonze ◽  
E Anklam ◽  
A M Betbeder ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Red Wine ◽  
Collaborative Study ◽  
White Wine ◽  
Fluorometric Detection ◽  
Immunoaffinity Column ◽  
Relative Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract The accuracy, repeatability, and reproducibility characteristics of a liquid chromatographic method for the determination of ochratoxin A (OTA) in white wine, red wine, and beer were established in a collaborative study involving 18 laboratories in 10 countries. Blind duplicates of blank, spiked, and naturally contaminated materials at levels ranging from ≤0.01 to 3.00 ng/mL were analyzed. Wine and beer samples were diluted with a solution containing polyethylene glycol and sodium hydrogen carbonate, and the diluted samples were filtered and cleaned up on an immunoaffinity column. OTA was eluted with methanol and quantified by reversed-phase liquid chromatography with fluorometric detection. Average recoveries from white wine, red wine, and beer ranged from 88.2 to 105.4% (at spiking levels ranging from 0.1 to 2.0 ng/mL), from 84.3 to 93.1% (at spiking levels ranging from 0.2 to 3.0 ng/mL), and from 87.0 to 95.0% (at spiking levels ranging from 0.2 to 1.5 ng/mL), respectively. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 6.6 to 10.8% for white wine, from 6.5 to 10.8% for red wine, and from 4.7 to 16.5% for beer. Relative standard deviations for between-laboratories reproducibility (RSDR) ranged from 13.1 to 15.9% for white wine, from 11.9 to 13.6% for red wine, and from 15.2 to 26.1% for beer. HORRAT values were ≤0.4 for the 3 matrixes.

scholarly journals Determination of Atrazine in Water by Magnetic Particle Immunoassay: Collaborative Study

1996 ◽  
Vol 79 (2) ◽  
pp. 529-537 ◽  
Author(s):  
Mary C Hayes ◽  
Scott W Jourdan ◽  
David P Herzog ◽  
P Barnes ◽  
C Charan ◽  
...  
Keyword(s):  
Detection Limit ◽  
Water Sample ◽  
Magnetic Particle ◽  
Collaborative Study ◽  
Study Data ◽  
Collaborative Studies ◽  
Enzyme Conjugate ◽  
Repeatability And Reproducibility ◽  
The Mean

Abstract A collaborative study was performed to determine mean recovery and precision for analysis of atrazine in drinking and surface waters by immunoassay. The study design was based on the blind duplicate test plan for collaborative studies. Three blank waters (municipal drinking water, well water, and surface water) were spiked at 3 atrazine levels. Two water samples with naturally incurred atrazine loads were also spiked with atrazine at 3 levels. In the enzyme-linked immunoassay method, the water sample is mixed with a pesticide–enzyme conjugate and added to paramagnetic particles with triazine-specific antibodies attached. After separation of antibody-bound atrazine and atrazine–enzyme conjugate from free components, the bound enzyme conjugate catalyzes a reaction producing a colored end product. The color developed is inversely proportional to the original concentration of atrazine in the water sample. Fourteen laboratories participated in the collaborative study. Data were analyzed for repeatability and reproducibility, and average recoveries at the spike levels were calculated. Over the concentration range tested, the mean recovery of atrazine spiked into blank and pesticide-contaminated waters was 104%. Overall RSDRaveraged about 40% for atrazine concentrations near the method detection limit (0.05 μg/L) and about 15% at concentrations above 5 times the detection limit (0.25 μg/L). Corresponding single-analyst RSDr values were 24 and 10%. Recovery and precision for the 3 blank water matrixes and the waters that had been naturally contaminated with atrazine showed no significant differences. The magnetic particle immunoassay

Liquid Chromatographic Method for Determination of Iodine in Milk: Collaborative Study

1993 ◽  
Vol 76 (4) ◽  
pp. 711-719 ◽  
Author(s):  
David Sertl ◽  
William Malone ◽  
◽  
P Beljaars ◽  
C Blake ◽  
...  
Keyword(s):  
Membrane Filter ◽  
Collaborative Study ◽  
Reversed Phase ◽  
Powdered Milk ◽  
Insoluble Material ◽  
Relative Standard ◽  
Repeatability And Reproducibility ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract Nine laboratories participated in an AOAC International/ International Dairy Federation collaborative study on a liquid chromatographic (LC) method for determination of iodine in milk. Liquid milk is passed through a 25 000 MW membrane filter to remove protein and insoluble material. Iodine (in the form of iodide) in the clear filtrate is separated by reversed-phase ion-pair LC and is detected electrochemically. Participants analyzed 2 commercial pasteurized whole milks and 5 nonfat dry milk powders in blind duplicate. Each sample was tested in duplicate on 2 days. Repeatability and reproducibility standard deviations (sr and SR, respectively) and repeatability and reproducibility relative standard deviations (RSDr and RSDR, respectively) for determinations of iodine in whole milk (mean recovery, 86.7%) were as follows: sr, 22 μg/L; SR, 22 μg/L; RSDr, 8.2%; and RSDR, 8.3%. For powdered milk (mean recovery, 91 %), the values were as follows: sr, 0.14 μg/g; SR, 0.22 μg/g; RSDr, 9.0%; and RSDR, 12.7%. The method was adopted first action by AOAC International.

Determination of Dextran in Raw Cane Sugar by Roberts Copper Method: Collaborative Study

1988 ◽  
Vol 71 (2) ◽  
pp. 276-279
Author(s):  
Margaret A Clarke ◽  
Mary An Godshall
Keyword(s):  
Collaborative Study ◽  
Cane Sugar ◽  
Coefficients Of Variation ◽  
Raw Sugar ◽  
Repeatability And Reproducibility

Abstract A collaborative study was conducted using the Roberts copper method for the determination of dextran in raw cane sugars. Four samples were analyzed in duplicate, representing the range of dextran concentrations found in raw sugar. The overall repeatability and reproducibility coefficients of variation were 4.3 and 13.2%, respectively. The method has been adopted official first action.

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