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.

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.

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.

Liquid Chromatographic Determination of Penicillin V Potassium in Tablets: Collaborative Study

1989 ◽  
Vol 72 (6) ◽  
pp. 883-884
Author(s):  
Barry Mopper
Keyword(s):  
Collaborative Study ◽  
Potassium Phosphate ◽  
Internal Standard ◽  
Photometric Detection ◽  
Penicillin V ◽  
Relative Standard ◽  
Repeatability And Reproducibility ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for the determination of penicillin V potassium in tablets was collaboratively studied by 7 laboratories. The method uses an octadecyl silane reverse-phase column, a mobile phase of acetonitrile-methanol-O.OlM potassium phosphate monobasic (21 + 4 + 75 v/v/v), photometric detection at 225 nm, and sulfadimethoxine as an internal standard. Each collaborator received 6 samples: powdered composites of 2 commercial tablet preparations and 1 synthetic tablet powder mixture, each with blind duplicates. The mean repeatability and reproducibility relative standard deviations for commercial samples were, respectively, 1.10 and 1.46% (250 mg dosage), and 0.84 and 2.82% (500 mg dosage). The average standard recovery from the synthetic formulation was 99.1%, with repeatability and reproducibility relative standard deviations of 1.30 and 3.66%, respectively. The method has been adopted official first action.

scholarly journals Determination of Aflatoxins B1, B2, G1, and G2 and Ochratoxin A in Ginseng and Ginger by Multitoxin Immunoaffinity Column Cleanup and Liquid Chromatographic Quantitation: Collaborative Study

2008 ◽  
Vol 91 (3) ◽  
pp. 511-523 ◽  
Author(s):  
Mary W Trucksess ◽  
Carol M Weaver ◽  
Carolyn J Oles ◽  
Frederick S Fry ◽  
Gregory O Noonan ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
High Performance ◽  
Collaborative Study ◽  
Immunoaffinity Column ◽  
Relative Standard ◽  
Hydrogen Carbonate ◽  
Aqueous Sodium Hydrogen Carbonate ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract The accuracy, repeatability, and reproducibility characteristics of a method using multitoxin immunoaffinity column cleanup with liquid chromatography (LC) for determination of aflatoxins (AF; sum of aflatoxins B1, B2, G1, and G2) and ochratoxin A (OTA) in powdered ginseng and ginger have been established in a collaborative study involving 13 laboratories from 7 countries. Blind duplicate samples of blank, spiked (AF and OTA added) at levels ranging from 0.25 to 16.0 g/kg for AF and 0.25 to 8.0 g/kg for OTA were analyzed. A naturally contaminated powdered ginger sample was also included. Test samples were extracted with methanol and 0.5 aqueous sodium hydrogen carbonate solution (700 + 300, v/v). The extract was centrifuged, diluted with phosphate buffer (PB), filtered, and applied to an immunoaffinity column containing antibodies specific for AF and OTA. After washing the column withwater, the toxins were eluted from the column with methanol, and quantified by high-performance LC with fluorescence detection. Average recoveries of AF from ginseng and ginger ranged from 70 to 87 (at spiking levels ranging from 2 to 16 g/kg), and of OTA, from 86 to 113 (at spiking levels ranging from 1 to 8 g/kg). Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 2.6 to 8.3 for AF, and from 2.5 to 10.7 for OTA. Relative standard deviations for between-laboratory reproducibility (RSDR) ranged from 5.7 to 28.6 for AF, and from 5.5 to 10.7 for OTA. HorRat values were 2 for the multi-analytes in the 2 matrixes.

Determination of Total Taurine in Pet Foods by Liquid Chromatography of the Dansyl Derivative: Collaborative Study

2000 ◽  
Vol 83 (4) ◽  
pp. 784-788 ◽  
Author(s):  
Kieran McCarthy ◽  
Claudia Hischenhuber ◽  
Neil Joyce ◽  
G Cherix ◽  
C Hischenhuber ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Collaborative Study ◽  
Gradient Elution ◽  
Taurine Concentration ◽  
Dansyl Derivative ◽  
Relative Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method for the determination of total taurine in pet foods was evaluated in a collaborative study. Ten laboratories assayed 6 blind duplicate pairs of wet and dry pet foods. The taurine in the 6 sample pairs ranged from low (170 mg/kg) to high (2250 mg/kg) concentrations as is. Collaborators also assayed a sample of known taurine concentration for familiarization purposes. Samples were hydrolyzed to release bound taurine, which was subsequently converted to the dansyl derivative and quantitated by gradient-elution LC with fluorescence detection. Repeatability relative standard deviations, RSDr, ranged from 3.2 to 10.0%; reproducibility relative standard deviations, RSDR, ranged from 6.1 to 16.1%. The method has been adopted Official First Action status by AOAC INTERNATIONAL.

Liquid Chromatographic Method for Determination of Glycerol in Wine and Grape Juice: Collaborative Study

1992 ◽  
Vol 75 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Arthur Caputi ◽  
Eric Christensen ◽  
Nancy Biedenweg ◽  
Susan Miller
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Grape Juice ◽  
External Standard Method ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
External Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract An Ion-exchange liquid chromatographic method for the determination of glycerol in wine, white grape juice, and pink grape juice was collaboratively studied by 8 laboratories. Eight wine types and 12 juice samples were provided to each collaborator. Using a strong cation column, blind duplicates and standards were analyzed by an external standard method. Separate statistical evaluations were run on wine, white grape juice, and pink grape juice data. The averages of the relative standard deviations for repeatability, excluding outlying results, were 1.25% for the wine samples, 7.32% for the white grape juice samples, and 8.63% for the pink grape juice samples. The averages of the relative standard deviations for reproducibility, excluding outlying results, were 2.79% for the wine samples, 16.97% for the white grape juice samples, and 19.10% for the pink grape juice samples. The method has been adopted first action by AOAC International.

Liquid Chromatographic Method for Multiresidue Determination of Benzimidazoles in Beef Liver and Muscle: Collaborative Study

1991 ◽  
Vol 74 (3) ◽  
pp. 487-493 ◽  
Author(s):  
Leon W Levan ◽  
Charlie J Barnes
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Study Data ◽  
Beef Liver ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Repeatability And Reproducibility ◽  
Multiresidue Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of thiabendazole, 5-hydroxythiabendazole, oxfendazole, mebendazole (MBZ), and fenbendazole (FBZ) In cattle liver and muscle was collaboratively studied in 7 laboratories In 1986. For blind fortified samples containing 800 ppb FBZ, average recovery and relative standard deviations for repeatability and reproducibility (RSDr and RSDR) based on results from 6 of the participating laboratories were 83%, 12.7%, and 14.0%, respectively. Recoveries of FBZ from incurred liver samples were more variable. Recoveries of MBZ from livers fortified at the 100 ppb level were encouraging; however, the drug levels were too low in the incurred samples used for MBZ studies. Except for FBZ and MBZ In liver, the study data were not satisfactory. The method has been adopted official first action by AOAC for determination of 800-1600 ppb fenbendazole In liver. The analysis should be repeated using a smaller sample size when Initial analyses show levels greater than 1600 ppb FBZ.

Comparison of Kjeldahl Method for Determination of Crude Protein in Cereal Grains and Oilseeds with Generic Combustion Method: Collaborative Study

1993 ◽  
Vol 76 (4) ◽  
pp. 780-786 ◽  
Author(s):  
Ronald C Bicsak ◽  
◽  
R Boles ◽  
R Cathey ◽  
V Collins ◽  
...  
Keyword(s):  
Crude Protein ◽  
Animal Feed ◽  
Collaborative Study ◽  
Combustion Method ◽  
Cereal Grains ◽  
Relative Standard ◽  
Kjeldahl Method ◽  
Repeatability And Reproducibility ◽  
Standard Deviations

Abstract Seven laboratories participated in a collaborative study to extend the applicability of the AOAC generic combustion method for determination of crude protein in animal feed (990.03) to include determination in cereal grains and oilseeds. In the study, method 990.03 was compared with the AOAC mercury catalyst Kjeldahl method for determination of protein in grains (979.09) and crude protein in animal feed (954.01). The study also evaluated the effect on the results of fineness of grind. For determination of crude protein in grains and oilseeds by the combustion method, standard deviations for repeatability and reproducibility ranged from 0.10 to 0.37 and from 0.25 to 0.54, respectively, and relative standard deviations for repeatability and reproducibility ranged from 0.77 to 2.57% and from 1.24 to 3.15%, respectively. The combustion method was adopted first action by AOAC International for determination of crude protein in cereal grains and oilseeds containing 0.2- 20% nitrogen.

scholarly journals Liquid Chromatographic Determination of Fumonisins B1, B2, and B3 in Corn: AOAC–IUPAC Collaborative Study

1996 ◽  
Vol 79 (3) ◽  
pp. 688-696 ◽  
Author(s):  
Eric W Sydenham ◽  
Gordon S Shephard ◽  
Pieter G Thiel ◽  
Sonja Stockenström ◽  
Petra W Snijman ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Relative Standard ◽  
Valid Data ◽  
Liquid Chromatographic Determination ◽  
Standard Deviations ◽  
The Individual ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method for simultaneous determination of fumonisins B1 (FB1), B2 (FB2), and B3 (FB3) in corn was subjected to a collaborative study involving 12 participants from 10 countries, in which the accuracy and reproducibility characteristics of the method were established. Mean analyte recoveries from corn ranged from 81.1 to 84.2% for FB1 (at a spiking range of 500 to 8000 ng/g), from 75.9 to 81.9% for FB2 (at a spiking range of 200 to 3200 ng/g), and from 75.8 to 86.8% for FB3 (at a spiking range of 100 to 1600 ng/g). The valid data were statistically evaluated after exclusion of outliers. Relative standard deviations for within-laboratory repeatability ranged from 5.8 to 13.2% for FB1, from 7.2 to 17.5% for FB2, and from 8.0 to 17.2% for FB3. Relative standard deviations for between-laboratory reproducibility varied from 13.9 to 22.2% for FB1, from 15.8 to 26.7% for FB2, and from 19.5 to 24.9% for FB3. HORRAT ratios, calculated for the individual toxin analogues, ranged from 0.75 to 1.73. The LC method for determination of fumonisins B1, B2, and B3 in corn (at concentrations of 800–12800 ng total fumonisins/g) has been adopted by AOAC INTERNATIONAL.

Liquid Chromatographic Method for Determination of Technical Deltamethrin and Deltamethrin in Pesticide Formulations: CIPAC Collaborative Study

1990 ◽  
Vol 73 (5) ◽  
pp. 751-752
Author(s):  
Alan R Hanks
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Liquid Chromatographic Method ◽  
Pesticide Formulations ◽  
Relative Standard ◽  
Aoac Method ◽  
Repeatability And Reproducibility ◽  
Low Volume ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of deltamethrin In 6 different technical and formulated products was collaboratively studied In 14 laboratories. Each sample Is dissolved In lsooctane-1,4-dloxane (80 + 20), separated by LC on a silica gel column (cyano column for ultra low volume formulation), and detected at 254 nm (230 nm for ≤0.5% powder formulations). Quantitation Is done by peak area measurements. Relative standard deviations for repeatability and reproducibility ranged from 0.56 to 1.00% and from 0.76 to 2.90%, respectively. The method has been approved Interim official first action by AOAC as a CIPAC-AOAC method.

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