scholarly journals Determination of Deoxynivalenol in Soft Wheat by Immunoaffinity Column Cleanup and LC-UV Detection: Interlaboratory Study

2009 ◽  
Vol 92 (1) ◽  
pp. 181-189 ◽  
Author(s):  
Gary Neumann ◽  
Gary A Lombaert ◽  
Susan Kotello ◽  
Nicole Fedorowich ◽  
E Abdelaal ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Uv Detection ◽  
Interlaboratory Study ◽  
Soft Wheat ◽  
Immunoaffinity Column ◽  
Cereal Products ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract An interlaboratory study was conducted to assess the applicability of a previously validated method for the analysis of deoxynivalenol (DON) in cereal and cereal products to soft wheat in the range of >0.13.0 g/g. The study evaluated a generic method to determine DON at levels that bracket the existing Canadian guidelines for DON in soft wheat destined for use in baby foods and nonstaple foods. Collaborators selected one of 2 approved brands of DON immunoaffinity column for cleanup and their choice of qualified C18 liquid chromatographic (LC) column. Separation was by LC with UV detection. Blind duplicates from 5 levels of naturally contaminated wheat and a pair of spiked wheat samples were successfully analyzed by 12 laboratories in 8 countries. For samples naturally contaminated with DON from <0.12.2 g/g, the relative standard deviation of repeatability (RSDr) ranged from 3.1 to 14.8. For reproducibility, the RSDR ranged from 21.0 to 32.9 and the HorRat range was 1.0 to 1.9. Recoveries of 0.5 g/g DON spiked into wheat ranged from 66 to 98, with an average of 84. The RSDr was 5.4, the RSDR was 12.6, and the HorRat value was 0.7.

scholarly journals Determination of Deoxynivalenol in Cereals and Cereal Products by Immunoaffinity Column Cleanup with Liquid Chromatography: Interlaboratory Study

2005 ◽  
Vol 88 (4) ◽  
pp. 1197-1204 ◽  
Author(s):  
Susan J MacDonald ◽  
Danny Chan ◽  
Paul Brereton ◽  
Andrew Damant ◽  
Roger Wood ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Wheat Flour ◽  
Interlaboratory Study ◽  
Immunoaffinity Column ◽  
Breakfast Cereal ◽  
Cereal Products ◽  
Sample Extract ◽  
Relative Standard

Abstract An interlaboratory study was performed on behalf of the UK Food Standards Agency to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatographic (LC) method for the determination of deoxynivalenol in a variety of cereals and cereal products at proposed European regulatory limits. The test portion was extracted with water. The sample extract was filtered and applied to an immunoaffinity column. After being washed with water, the deoxynivalenol was eluted with acetonitrile or methanol. Deoxynivalenol was quantitated by reversed-phase LC with UV determination. Samples of artificially contaminated wheat-flour, rice flour, oat flour, polenta, and a wheat based breakfast cereal, naturally contaminated wheat flour, and blank (very low level) samples of each matrix were sent to 13 collaborators in 7 European countries. Participants were asked to spike test portions of all samples at a range of deoxynivalenol concentrations equivalent to 200–2000 ng/g deoxynivalenol. Average recoveries ranged from 78 to 87%. Based on results for 6 artificially contaminated samples (blind duplicates), the relative standard deviation for repeatability (RSDr) ranged from 3.1 to 14.1%, and the relative standard deviation for reproducibility (RSDR) ranged from 11.5 to 26.3%. The method showed acceptable within-laboratory and between-laboratory precision for all 5 matrixes, as evidenced by HorRat values <1.3.

scholarly journals Liquid Chromatographic Determination of Deoxynivalenol in Baby Food and Animal Feed: Interlaboratory Study

2006 ◽  
Vol 89 (4) ◽  
pp. 1012-1020 ◽  
Author(s):  
Joerg Stroka ◽  
Michelle Derbyshire ◽  
Carsten Mischke ◽  
Massimo Ambrosio ◽  
Katy Kroeger ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
High Performance ◽  
Animal Feed ◽  
Chromatographic Determination ◽  
Baby Food ◽  
Interlaboratory Study ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract An interlaboratory study was conducted for the determination of deoxynivalenol in baby food and animal feed by high-performance liquid chromatography with UV detection. The study included 14 participants representing a cross section of industry, official food control, and research facilities. Mean recoveries reported ranged from 89% (at 120 g/kg) to 85% (at 240 g/kg) for baby food and from 100% (at 200 g/kg) to 93% (at 400 g/kg) for animal feed. On the basis of the results for spiked samples (blind duplicates at 2 levels), as well as those for naturally contaminated samples (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) in analyses of baby food ranged from 6.4 to 14.0% and in analyses of animal feed, from 6.1 to 16.5%. The relative standard deviation for reproducibility (RSDR) in analyses of baby food ranged from 9.4 to 19.5% and in analyses of animal feed, from 10.5 to 25.2%. The HorRat values ranged from 0.4 to 1.0 and from 0.7 to 1.3, for baby food and animal feed, respectively. The method showed acceptable performance for within-laboratory and between-laboratory precision for each matrix, as required by European legislation.

scholarly journals Immunoaffinity Column Cleanup with Liquid Chromatography Using Post-Column Bromination for Determination of Aflatoxins in Hazelnut Paste: Interlaboratory Study

2005 ◽  
Vol 88 (2) ◽  
pp. 526-535 ◽  
Author(s):  
Hamide Z Senyuva ◽  
John Gilbert
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Aflatoxin B1 ◽  
The United States ◽  
Interlaboratory Study ◽  
Immunoaffinity Column ◽  
Test Portion ◽  
Relative Standard

Abstract An interlaboratory study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for determination of aflatoxin B1 and total aflatoxins in hazelnut paste at European regulatory limits. The test portion was extracted with methanol–water (6 + 4). The extract was filtered, diluted with phosphate-buffered saline (PBS) solution to a specified solvent concentration, and applied to an immunoaffinity column containing antibodies specific to aflatoxins. The aflatoxins were removed from the immunoaffinity column with methanol, and then quantified by reversed-phase LC with post-column derivatization (PCD) involving bromination. The PCD was achieved with electrochemically generated bromine (Kobra Cell®) followed by fluorescence detection (except for one participant who used pyridinum hydrobromide perbromide for bromination). Hazelnut paste, both naturally contaminated with aflatoxins and blank (<0.1 ng/g) for spiking by participants with aflatoxins, was sent to 14 collaborators in Belgium, The Netherlands, Spain, Turkey, the United Kingdom, and the United States. Test portions were spiked at levels of 4.0 and 10.0 ng/g for total aflatoxins by participants using supplied total aflatoxins standards. Recoveries for total aflatoxins and aflatoxin B1 averaged from 86 to 89%. Based on results for naturally contaminated samples (blind duplicates at 3 levels ranging from 4.0 to 11.8 ng/g total aflatoxins), the relative standard deviation for repeatability (RSDr) ranged from 2.3 to 3.4% for total aflatoxins and from 2.2 to 3.2% for aflatoxin B1. The relative standard deviation for reproducibility (RSDR) ranged from 6.1 to 7.0% for total aflatoxins and from 7.3 to 7.8% for aflatoxin B1. The method showed exceptionally good within-laboratory and between-laboratory precision for hazelnut paste, as evidenced by HORRAT values, which in all cases were significantly below target levels, the low levels of determination for both aflatoxin B1 and total aflatoxins.

scholarly journals Immunoaffinity Column Cleanup with Liquid Chromatography for Determination of Aflatoxin B1 in Corn Samples: Interlaboratory Study

2007 ◽  
Vol 90 (3) ◽  
pp. 765-772 ◽  
Author(s):  
Carlo Brera ◽  
Francesca Debegnach ◽  
Valentina Minardi ◽  
Elena Pannunzi ◽  
Barbara De Santis ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Aflatoxin B1 ◽  
Interlaboratory Study ◽  
Precolumn Derivatization ◽  
Immunoaffinity Column ◽  
Relative Standard ◽  
Postcolumn Derivatization

Abstract An interlaboratory study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for the determination of aflatoxin B1 levels in corn samples, enforced by European Union legislation. A test portion was extracted with methanolwater (80 + 20); the extract was filtered, diluted with phosphate-buffered saline solution, filtered on a microfiber glass filter, and applied to an immunoaffinity column. The column was washed with deionized water to remove interfering compounds, and the purified aflatoxin B1 was eluted with methanol. Aflatoxin B1 was separated and determined by reversed-phase LC with fluorescence detection after either pre- or postcolumn derivatization. Precolumn derivatization was achieved by generating the trifluoroacetic acid derivative, used by 8 laboratories. The postcolumn derivatization was achieved either with pyridinium hydrobromide perbromide, used by 16 laboratories, or with an electrochemical cell by the addition of bromide to the mobile phase, used by 5 laboratories. The derivatization techniques used were not significantly different when compared by the Student's t-test; the method was statistically evaluated for all the laboratories. Five corn sample materials, both spiked and naturally contaminated, were sent to 29 laboratories (22 Italian and 7 European). Test portions were spiked with aflatoxin B1 at levels of 2.00 and 5.00 ng/g. The mean values for recovery were 82% for the low level and 84% for the high contamination level. Based on results for spiked samples (blind pairs at 2 levels) as well as naturally contaminated samples (blind pairs at 3 levels), the values for relative standard deviation for repeatability (RSDr) ranged from 9.9 to 28.7%. The values for relative standard deviation for reproducibility (RSDR) ranged from 18.6 to 36.8%. The method demonstrated acceptable within- and between-laboratory precision for this matrix, as evidenced by the HorRat values.

scholarly journals Liquid Chromatographic Method with Immunoaffinity Column Cleanup for Determination of Ochratoxin A in Barley: Collaborative Study

2000 ◽  
Vol 83 (6) ◽  
pp. 1377-1383 ◽  
Author(s):  
A Catherine Entwisle ◽  
Alison C Williams ◽  
Peter J Mann ◽  
Philip T Slack ◽  
John Gilbert
Keyword(s):  
Standard Deviation ◽  
Ochratoxin A ◽  
Relative Standard Deviation ◽  
Limit Of Detection ◽  
Collaborative Study ◽  
Immunoaffinity Column ◽  
Low Level ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A collaborative study was conducted to evaluate a liquid chromatographic (LC) method with immunoaffinity column cleanup for determination of ochratoxin A. The method was tested at 3 concentration levels of ochratoxin A in barley, which represent possible future European regulatory limits. The test portion was extracted with acetonitrile–water by blending at high speed. The extract was filtered, diluted with phosphate-buffered saline (PBS), and applied to an ochratoxin A immunoaffinity column. The column was washed with water and the ochratoxin A eluted with methanol. The solvent was then evaporated and the residue redissolved in injection solvent. After injection of this solution onto reversed-phase LC column, ochratoxin A was measured by fluorescence detection. Eight samples of low level naturally contaminated barley and 2 samples of blank barley (ochratoxin A not found at the limit of detection of 0.2 μg/kg at the signal-to-noise ratio of 3 to 1) were sent, along with ampules of ochratoxin A, calibrant, and spiking solutions, to 15 laboratories in 13 different European countries. Test portions were spiked with ochratoxin A at levels of 4 ng/g, and recoveries ranged from 65 to 113%. Based on results for spiked samples (blind duplicates) and naturally contaminated samples (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) ranged from 4 to 24%, and the relative standard deviation for reproducibility (RSDR) ranged from 12 to 33%. The method showed acceptable within- and between-laboratory precision, as evidenced by HORRAT values, at the low level of determination for ochratoxin A in barley.

scholarly journals Liquid Chromatographic Determination of Ampicillin Residues in Porcine Muscle Tissue by a Multipenicillin Analytical Method: European Collaborative Study

2002 ◽  
Vol 85 (4) ◽  
pp. 889-900 ◽  
Author(s):  
Eric Verdon ◽  
Pierric Couëdor ◽  
Pierre Maris ◽  
Michel Laurentie ◽  
P Batjoens ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Muscle Tissue ◽  
Phosphate Buffer ◽  
Collaborative Study ◽  
Porcine Muscle ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A collaborative study involving 14 laboratories was conducted to determine residues of ampicillin in porcine muscle tissue by using a liquid chromatographic method developed for multipenicillin analysis that can quantitate 8 penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, amoxicillin, nafcillin, oxacillin, cloxacillin, and dicloxacillin) at trace levels in muscle tissue. This method involves extraction of the penicillins with phosphate buffer, pH 9, followed cleanup and concentration on a C18 solid-phase extraction column and reaction with benzoic anhydride at 50°C and with 1,2,4-triazole and mercury(II) chloride solution, pH 9.0, at 65°C. The derivatized compounds are eluted isocratically on a C8 column with a mobile phase of acetonitrile and phosphate buffer (pH 6; 0.1M) containing sodium thiosulfate and the ion-pair reagent tetrabutylammonium hydrogen sulfate. The penicillins are detected by UV absorption at 325 nm. The limit of detection and the limit of determination (quantitation) of the method were calculated to be approximately 3–5 and 25 μg/kg, respectively, in accordance with the criteria of European Union (EU) Decision No. 93/256/EEC. In this first interlaboratory study, collaborators were instructed to monitor 4 different penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, and amoxicillin) by analyzing 8 blind samples of muscle tissue in triplicate. These samples were prepared from 2 materials containing different concentrations of incurred ampicillin (63.5 μg/kg for material No. 1 and 358.1 μg/kg for material No. 2) and 1 blank material. The repeatability relative standard deviation and the reproducibility relative standard deviation were 10.2 and 17.4%, respectively, for material No. 1 and 7.0 and 16.0%, respectively, for material No. 2. These results demonstrate that the method is suitable for the determination of ampicillin residues in muscle tissue at the EU maximum residue limit (50 μg/kg) and above. However, the identification of positives by this procedure may need additional confirmation by techniques with greater specificity, such as liquid chromatography combined with mass spectrometry, or tandem mass spectrometry. Investigations regarding the basis of interlaboratory testing studies will further demonstrate the suitability of multiresidue methodology for detecting and quantitating other compounds in the family of penicillin antibiotics.

scholarly journals Determination of Aflatoxin B1 in Baby Food (Infant Formula) by Immunoaffinity Column Cleanup Liquid Chromatography with Postcolumn Bromination: Collaborative Study

2001 ◽  
Vol 84 (4) ◽  
pp. 1116-1124 ◽  
Author(s):  
Joerg Stroka ◽  
Elke Anklam ◽  
Urban Joerissen ◽  
John Gilbert ◽  
A Barmark ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Infant Formula ◽  
Aflatoxin B1 ◽  
Collaborative Study ◽  
Baby Food ◽  
Immunoaffinity Column ◽  
Relative Standard

Abstract A collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for determination of aflatoxin B1 in a milk powder based infant formula at a possible future European regulatory limit (0.1 ng/g). The test portion was extracted with methanol–water (8 + 2 [v + v]), filtered, diluted with water, and applied to an immunoaffinity column. The column was washed with water to remove interfering compounds, and the purified aflatoxin B1 was eluted with methanol. The separation and determination of the aflatoxin B1 was performed by reversed-phase LC and detected by fluorescence after postcolumn derivatization (PCD) involving bromination. PCD was achieved with either pyridinum hydrobromide perbromide (PBPB) or an electrochemical (Kobra) cell by addition of bromide to the mobile phase. The baby food (infant formula) test samples, both spiked and naturally contaminated with aflatoxin B1, were sent to 14 laboratories in 13 different European countries. Test portions were spiked at levels of 0.1 and 0.2 ng/g for aflatoxin B1. Recoveries ranged from 101 to 92%. Based on results for spiked test samples (blind pairs at 2 levels) and naturally contaminated test samples (blind pairs at 3 levels), the relative standard deviation for repeatability (RSDr) ranged from 3.5 to 14%. The relative standard deviation for reproducibility (RSDR) ranged from 9 to 23%. Nine participants used PBPB derivatization, and 5 particpants used the Kobra cell. There was no evidence of method performance depending on the derivatization method used. The method showed acceptable within- and between-laboratory precision for baby food matrix, as evidenced by HORRAT values, at the target levels of determination for aflatoxin B1.

Liquid Chromatographic Method for Determination of Explosives Residues in Soil: Collaborative Study

1990 ◽  
Vol 73 (4) ◽  
pp. 541-552 ◽  
Author(s):  
Christopher F Bauer ◽  
Stephan M Koza ◽  
Thomas F Jenkins
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Contaminated Soils ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Explosives Residues ◽  
Liquid Chromatographic

Abstract A collaborative study of a sonic extraction/liquid chromatographic method for determining nitroaromatic and nitramlne explosives In soil was conducted at 8 participating laboratories. Analytes HMX, RDX, TNB, DNB, tetryl, TNT, and 2,4-DNT were measured In duplicate for 4 field-contaminated soils and 4 spiked standard-matrix soils. Concentrations ranged from detection limits of about 1 μg/g to nearly 1000 μg/g. Results were evaluated with and without data Identified as outliers, which were often caused by electronic integrator miscalculation of chromatographic peak response. When outliers are excluded, method repeatability (within-laboratory relative standard deviation) for all analytes except tetryl Is less than 5% for spiked soils and less than 18% for fieldcontaminated soils. Relative standard deviation generally decreases as analyte concentration Increases. Reproducibility (between-laboratory relative standard deviation), except for tetryl and DNT, Is less than 7% for spiked soils and 26% for fleld-contamlnated soils. Thus, collaborators have nearly equivalent performance on spiked samples. For fleld-contamlnated soils, some additional Imprecision seems to result from the variability of extraction recoveries. Analyte recoveries from spiked soils are 95-97% for HMX, RDX, TNT, and DNT (similar to recoveries from aqueous samples); 92-93% for DNB and TNB; and 70% for tetryl. Poor results for tetryl (due to thermal degradation) are correctable If sonic bath temperatures are maintained near ambient. The method has been approved Interim official first action by AOAC.

Liquid Chromatographic Determination of Narasin in Feed Premixes

1985 ◽  
Vol 68 (3) ◽  
pp. 417-418 ◽  
Author(s):  
Raymond L Hussey ◽  
Thomas D Macy ◽  
John Moran ◽  
Andrew Loh
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Chromatographic Determination ◽  
Bioassay Method ◽  
Water Solvent ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed to determine narasin in feed premixes. Narasin is extracted from the premix with a methanol-water solvent, and the extracted solution is assayed by using LC. Recovery of narasin from a 12.5 g/lb premix is quantitative (100%), with a relative standard deviation of 1.44%. The results correlated well (coefficient 0.92) with a turbimetric bioassay method.

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.

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