Pesticides Residues in Various Cheese Types

The present paper refers to the comparative verification of the recovery percentage (R-factor) for the gas-chromatographic calculation of certain cheese types with high fat content, by using a few different concentration standards. The work was performed on samples taken from three types of cheese from the same producer from the Bihor County, which is Dalia pressed cheese (C), Mozarella (M) and kneaded cheese (B). All products have a high fat content (>35 % DS∗). The recovery percentage has been calculated working in the same separation and purification conditions (using the same methods) for all the tests: by controlled addition of 25 ppb and 50 ppb concentration sample. In the calculation it was used the concrete value of the interest aria of the drop found in the sample as it was and in the test that has been deliberately contaminated [1]. The added test is a complex type, produced by the RESTEK company cat. No 32292, Lot nr A021837, “Organochlorine pesticide Mix AB ≠2, with initial concentration of 200 ppb. The R factor was calculated for all the standard organochlorine compounds that can be found in the analyzed cheese tests, separately for the two standard concentrations. The resulted values (mean of each two calculations) are written in Tab. 1. Recovery degree, R – cheese POC *