Eric Sizoo

National Institute for Public Health and the Environment (RIVM), Utrecht, Utrecht, Netherlands

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Publications (9)17.18 Total impact

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    Journal of AOAC International 01/2011; 94(3). · 1.39 Impact Factor
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    ABSTRACT: A method for the determination of fumonisin B1 (FB1) and B2 (FB2) in different commercial maize-based products for infants and young children was developed and tested in a limited validation study involving 3 laboratories. The method used extraction at 55 °C with an acidic mixture of methanol-acetonitrile-phosphate/citrate buffer, clean-up through immunoaffinity column and fumonisin determination by high performance liquid chromatography with automated pre-column derivatisation with o-phthaldialdehyde. Recovery experiments were performed at five spiking levels in the ranges of 80-800 μg/kg FB1 and 20-200 μg/kg FB2. Mean recoveries ranged from 83 to 97% for FB1 and from 61 to 78% for FB2. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 5 to 12% for FB1 and from 8 to 13% for FB2, whereas relative standard deviation for between-laboratory reproducibility (RSDR) ranged from 6 to 10% for FB1 and from 9 to 16% for FB2. The limit of quantification of the method (signal to noise ratio of 6) was 2.8 μg/kg for FB1 and 2.2 μg/kg for FB2. Fumonisins were found in 6 out of 19 maize-based baby foods obtained from the Italian retail market at levels up to 53 μg/kg.
    World Mycotoxin Journal 05/2010; 3(2):135-146. DOI:10.3920/WMJ2010.1213 · 2.38 Impact Factor
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    ABSTRACT: Acrylamide, a probable human carcinogen, was detected in various heat-treated foods such as French fries and potato crisps. Recently, positive associations have been found between dietary acrylamide intakes, as estimated with a food frequency questionnaire using an acrylamide database, and cancer risk in some epidemiological studies. As acrylamide levels vary considerably within the same type of foods, a validation study was performed to investigate whether use of an acrylamide food database containing calculated mean acrylamide content, based on extensive sampling and chemical analysis of Dutch foods (several samples per food), can classify subjects with respect to true acrylamide intake. We used the data from a 24-h duplicate diet study. The acrylamide content of 39 Dutch 24-h duplicate diets collected in 2004 was estimated using the mean acrylamide levels of foods available from the database and the menu list, on which the participants of the duplicate diet study had listed the amounts of individual foods and drinks in household units. Next, the acrylamide content of the total duplicate diets was analytically measured and correlated to the estimated acrylamide contents. The Spearman's correlation coefficient between chemically determined acrylamide content and the calculated acrylamide content of the duplicate diets was 0.82 (P<0.001). This study indicates that it is possible to classify subjects with respect to acrylamide intake if mean instead of actual content of each food is applied. The database can therefore be applied in epidemiological studies on acrylamide intake and cancer risk, such as the Netherlands Cohort Study on Diet and Cancer.
    European journal of clinical nutrition 03/2010; 64(5):534-40. DOI:10.1038/ejcn.2010.17 · 2.95 Impact Factor
  • World Mycotoxin Journal 11/2009; 2(4):451-459. DOI:10.3920/WMJ2009.1167 · 2.38 Impact Factor
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    ABSTRACT: Infants have a more restricted diet and they generally consume more food on a body weight basis than adults. Therefore, the significance and potential health risk of any contaminant in foods consumed by infants is increased and diligent attention must be paid to this particular area. The present study aims to determine the occurrence of aflatoxin M1 (AFM1), aflatoxin B1 (AFB1) and ochratoxin A (OTA) in processed cereal-based foods (flours) and infant formulae (milk powder) available in the Portuguese market, both sold as conventional and organic origin. Mycotoxin determination was carried out using a method previously applied to duplicate diet samples. This method employed chloroform extraction, liquid–liquid extraction, immunoaffinity column (IAC) cleanup and HPLC analysis with fluorescence detection after post-column derivatisation. Quantification limits were 0.014, 0.004 and 0.028μg kg−1 for AFM1, AFB1 and OTA, respectively. These toxins could only be quantified in 12 of 27 analysed samples (15 positive results): two samples with AFM1, two samples with AFM1 and OTA, one sample with AFB1 and OTA and seven samples with OTA. Positive results concerned four for AFM1 (26%), one for AFB1 (7%) and ten for OTA (67%). For these samples, contents ranged between 0.017–0.041μg AFM1 kg−1, 0.034–0.212μg OTA kg−1, and one sample had a value of 0.009μg AFB1 kg−1. Considering the presented results, we could provisionally conclude that the presence of these mycotoxins in baby foods does not constitute a public health problem. These are the first results concerning the occurrence of mycotoxins in marketed baby foods in Portugal and this is the first study using the HPLC method, proposed for duplicate diets, in baby food sample analysis.
    Food Analytical Methods 03/2008; 3(1):22-30. DOI:10.1007/s12161-008-9064-x · 1.80 Impact Factor
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    ABSTRACT: An interlaboratory trial for determination of zearalenone (ZON) in baby food and animal feed was conducted. The study involved 39 participants in 16 European Union member states, as well as Turkey, Uruguay, and China, representing a cross-section of industry, and official food control and research institutes. The method is based on immunoaffinity column cleanup followed by high-performance liquid chromatography using fluorimetry (HPLC-FI). The test portion of the sample is extracted with methanol-water (75 + 25, v/v). The sample extract is filtered, diluted, and passed over an immunoaffinity column. ZON is eluted with methanol. The separation and determination of ZON is performed by reversed-phase HPLC-FI with an excitation wavelength of 274 nm and an emission wavelength of 446 nm. Test portions of the samples were spiked at levels of 20 and 30 microg/kg ZON in baby food and at levels of 100 and 150 microg/kg ZON in animal feed. Mean recoveries from each participant ranged from 78 to 119% with an average value of 92% for baby food and from 51 to 122% with an average value of 74% for animal feed. Based on results for spiked samples (blind duplicates at 2 levels), as well as naturally contaminated samples (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) in baby food ranged from 2.8 to 9.0%. For animal feed, this value ranged from 5.7 to 9.5%. The relative standard deviation for reproducibility (RSDR) in baby food ranged from 8.2 to 13.3%, and for animal feed this value ranged from 15.5 to 21.4%. The Horwitz ratio (HorRat) in baby food ranged from 0.3 to 0.4, and for animal feed this value ranged from 0.6 to 0.9. The method showed acceptable within- and between-laboratory precision for each matrix, as required by European legislation.
    Journal of AOAC International 01/2007; 90(6):1598-609. · 1.39 Impact Factor
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    ABSTRACT: A method was developed for the determination of aflatoxin B1 in medical herbs (senna pods, botanical name Cassia angustifolia; devil's claw, botanical name Harpagophytum procumbens; and ginger roots, botanical name Zingiber officinale). The method, which was tested in a mini-collaborative study by 4 laboratories, is based on an immunoaffinity cleanup followed by reversed-phase high-performance liquid chromatography separation and fluorescence detection after post-column derivatization. It allows the quantitation of aflatoxin B1 at levels lower than 2 ng/g. A second extractant (acetone-water) was tested and compared to the proposed methanol-water extractant. Several post-column derivatization options (electrochemically generated bromine, photochemical reaction, and chemical bromination) as well as different integration modes (height versus area) were also investigated. No differences were found depending on the choice of derivatization system or the signal integration mode used. The method was tested for 3 different matrixes: senna pods, ginger root, and devil's claw. Performance characteristics were established from the results of the study and resulted in HorRat values ranging from 0.12 to 0.75 with mean recoveries from 78 to 91% for the extraction with methanol-water and HorRat values ranging from 0.10-1.03 with mean recoveries from 98 to 103% for the extraction with acetone-water. As a result, the method, with all tested variations, was found to be fit-for-purpose for the determination of aflatoxin B1 in medical herbs at levels of 1 microg/kg and above.
    Journal of AOAC International 01/2006; 89(3):595-605. · 1.39 Impact Factor
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    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 microg/kg) to 85% (at 240 microg/kg) for baby food and from 100% (at 200 microg/kg) to 93% (at 400 microg/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.
    Journal of AOAC International 01/2006; 89(4):1012-20. · 1.39 Impact Factor
  • Eric A Sizoo, Hans P van Egmond
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    ABSTRACT: In the spring and autumn of 1994, a total diet study, in which 123 participants collected duplicates of their 24-hour diets, was carried out. The goal of this study was to determine the mass fractions of a number of analytes in these duplicate diets, so as to be able to establish oral daily intake values. After measurements were carried out for pesticides, PCBs, elements, sterols, nitrate and nitrite, and fatty acids, the duplicate diet study was concluded with analyses for aflatoxin M1, aflatoxin B1 and ochratoxin A. For this purpose a method of analysis was developed, that could simultaneously determine these mycotoxins at very low levels. The method involved chloroform extraction, liquid-liquid extraction, immunoaffinity cleanup and liquid chromatography. The method was supplemented with a procedure to confirm the identity of chromatographic peaks, assumed to represent aflatoxin M1, aflatoxin B1 and ochratoxin A. The method was in-house validated. Recoveries ranged from 68-74% for aflatoxin M1 (at spiking levels from 30-120 ng/kg, c.v. 7.6%), from 95-97% for aflatoxin B1 (at spiking levels from 50-200 ng/kg, c.v. 2.8%), and from 75-84% for ochratoxin A (at spiking levels from 150-600 ng/kg, c.v. 4.3%). Limits of quantitation (defined as signal/noise = 10) were estimated to be 24, 5 and 16 ng/kg lyophilised material for aflatoxin M1, aflatoxin B1 and ochratoxin A respectively. The newly developed method was used to analyse 123 samples of 24-hour diets. Aflatoxin M1 was detectable in 48% of the samples; the toxin contents remained below the limit of quantitation in all samples. Aflatoxin B1 could be detected in 42% of the samples; in 25% of the samples the levels were above the limit of quantitation. Ochratoxin A could be quantified in all samples. The analytical results were further processed to estimate levels of intake. Intake levels for the aflatoxins were very low, and could not reliably be established. The mean ochratoxin A intake was estimated to be 1.2 ng/kg body weight per day. This is well below the tolerable daily intake established by JECFA at 14 ng/kg body weight per day. The current dietary intake of ochratoxin A in the Netherlands is concluded to pose no appreciable health risk.
    Food Additives and Contaminants 03/2005; 22(2):163-72. DOI:10.1080/02652030400029439 · 2.13 Impact Factor