S.L. 437.77 ст. 7using the m = amount calculated as P(sample) P(st ) = 1 reference P(st ) = 2 reference r(st) = V = m V = final e x t made (5.3) M = mass V = volume f V = volume c If the aflatoxin B 7.1. measurement. 8. see under 9. see under 10. 10.1. A stuffs gave the term at the 95% the same similarly 3534 - 1977

Calculation of results

Calculate the aflatoxin B content (µm/kg) present in the sample, 1 formula:

aflatoxin B content in èmg/kg = m x V 1 e x t V x M x V m f V c where: of aflatoxin B in ng represented by the B peak of the sample, 1 1 follows:

P(sample) m - x 2 r(st) P(st ) + P(st ) 1 2 = peak area of aflatoxin B for the sample 1 peak area of aflatoxin B resulting from the preceeding injection of 1 standard (3.13.3)

peak area of aflatoxin B resulting from the following injection of 1 standard (3.13.3)

injected amount of aflatoxin B in the reference standard (3.13.3) in ng 1 volume of the injected sample extract in ml volume of sample extract in ml, allowing for any dilution that was of sample in g of filtrate transferred to Florisil cartridge (5.4.1.2) in ml of chloroform, used for the extraction of the sample in ml procedure is followed as in this protocol, the formula reduces to:

content in µg/kg = 20 × m. 1 Calculations of the results may also be done by peak height

Repeatability: 10.1

Reproducibility: 10.1 Observations

Precision * collaborative study , carried out at the international level on mixed feeding results for repeatability and reproducibility indicated in Table 1. The repeatability (r) used here is defined as the largest ratio which is not significant probability level for comparison of two readings of the same sample in laboratory under similar conditions. The term reproducibility (R) is defined for comparing two different laboratories. In accordance to ISO † 2.35 and European Union Commission Decision 89/610/EEC r and R in Table 1 in terms of coefficients of variation. Table 1 Repeatability (r) and reproducibility (R) expressed as ratios and corresponding coefficients of variation (15 laboratories)

van, Heisterkamp, S.H. and Paulsch, W.E. (1991). Food Additives and Contaminants 8, 17-

Level r R CV (*) CV r R (µg/kg) (%) (%) 8 & 14 1,4 1,7 11 18 (*) CV = coefficient of variation

10.2. Stabilization of chloroform (3.1) The adsorption characteristics of the florisil cartridge may stabilizers other than ethanol are used. This should be verified in accordance 10.3 when the chloroform described is not available. 10.3. Accuracy The correct applications of the method shall be verified by making measurements on certified reference materials. If these are not performance of the method should be verified by recovery experiments fortified blank samples. The deviation of the mean from the actual value, as a percentage of the actual value, shall not lie outside the limits -20

Figure 1: Column-cartridge assembly Flow diagram of the LC system with iodine post-column derivatization

Compensation for drift in aflatoxin B response by injecting reference 1 standard (3.13.3) at regular intervals

OBSERVATIONS CONCERNING METHODS A AND B

Defatting containing more than 5% fats must be defatted with light petroleum (bp degrees C) after the preparations indicated in 5.1. cases, the analytical results must be expressed in terms of the weight of the sample.