View source for Summary - all-trans-retinol and 13-cis-retinol


<p><strong>EN 12823-1:2000 Foodstuffs - Determination of vitamin A by high performance liquid chromatography - part 1: measurement of all-trans-retinol and 13-cis-retinol</strong></p>


<p><strong>Scope</strong></p>


<p>This European Standard specifies a method for the determination of vitamin A in foodstuffs by high performance liquid chromatography (HPLC). The determination of vitamin A content is carried out by the measurement of all-trans-retinol, 13-cis-retinol and &beta;-carotene. This part covers the measurement of all-trans-retinol and 13-cis-retinol.</p>


<p>The extract obtained after saponification in this method can be used for the determination of &beta;-carotene, as specified in EN 12823-2:2000.</p>


<p><strong>Principle</strong></p>


<p>Retinol is saponified by using methanolic or ethanolic potassium hydroxide solution and extracted by an appropriate solvent. The determination is carried out by high performance liquid chromatography (HPLC) with either fluorometric (F) or ultra-violet (UV) detection. The substances are identified on the basis of the retention times and determined by the external standard procedure using peak ares or heights.</p>


<p><strong>Precision data from EN 12823-1:</strong></p>


<table style="border: 1px solid black;border-collapse: collapse;">
        <tr style="border: 1px solid black;border-collapse: collapse;">
            <th style="border: 1px solid black;border-collapse: collapse;">
                    <p>&nbsp;</p>

            </th>
            <th style="border: 1px solid black;border-collapse: collapse;">
                    <p> Margarine (CRM 122)
                        <br > all-trans-retinol
                        <br > </p>

            </th>
            <th style="border: 1px solid black;border-collapse: collapse;">
                    <p> Margarine (CRM 122)
                        <br > 13-cis-retinol
                        <br > </p>

            </th>
            <th style="border: 1px solid black;border-collapse: collapse;">
                    <p> Milk powder (CRM 421)
                        <br > all-trans-retinol
                        <br > </p>

            </th>
            <th style="border: 1px solid black;border-collapse: collapse;">
                    <p> Milk powder (CRM 421)
                        <br > 13-cis-retinol
                        <br > </p>

            </th>
        </tr>

        <tr style="border: 1px solid black;border-collapse: collapse;">
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> Repeatability standard deviation s
                    <sub>r</sub>, µg/100 g
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 28
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 3
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 14
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 1,5
                    <br > </p>
            </td>
        </tr>
        <tr style="border: 1px solid black;border-collapse: collapse;">
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> Repeatability coefficient of variation, % </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 3,8
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 7,7
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 2,1
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 5,0
                    <br > </p>
            </td>
        </tr>
        <tr style="border: 1px solid black;border-collapse: collapse;">
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> Repeatability limit r = [2,8 x s
                    <sub>r</sub>], µg/100 g
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 78,4
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 8,4
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 39,2
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 4,2
                    <br > </p>
            </td>
        </tr>
        <tr style="border: 1px solid black;border-collapse: collapse;">
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> Reproducibility standard deviation s
                    <sub>R</sub>, µg/100 g </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 73
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 12
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 22
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 7,2
                    <br > </p>
            </td>
        </tr>
        <tr style="border: 1px solid black;border-collapse: collapse;">
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> Reproducibility&nbsp;coefficient of variation, % </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 10,0
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 30,8
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 3,4
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 24,0
                    <br > </p>
            </td>
        </tr>
        <tr style="border: 1px solid black;border-collapse: collapse;">
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> Reproducibility limit r = [2,8 x s
                    <sub>R</sub>], µg/100 g </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 204,4
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 33,6
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 61,6
                    <br > </p>
            </td>
            <td style="border: 1px solid black;border-collapse: collapse;">
                <p> 20,2
                    <br > </p>
            </td>
        </tr>
</table>