Fruits, maximum residue limits

The European Community guidelines specify that the maximum residue limit (MRL) for alkylenebis(dithiocarbamates) in fruits and vegetables is 0.05 mg carbon disulfide (CS2)kg ... 

There may also be cases where the maximum amount of analyte permitted is fixed by law, i.e. statutory limits. For these, there may be laid down standard procedures for sampling. The Codex maximum residue limit for the pesticide cypermethrin is 2 mg kg-1 (at the time of writing) in both citrus fruits and peaches [13]. When preparing the sample for analysis you need to know that in the case of the citrus fruit you take the whole fruit - skin, pith, pips, flesh and juice - whereas in the case of peaches it is the fruit after removal of stems and stones, but the residue is calculated and expressed in terms of the whole commodity (including the stone) without stems [14]. In some instances, it may be necessary to take a certain number of samples and that these must be taken in the presence of a witness. 

The TMRC is based upon tolerances established for raw agricultural commodities. It assumes all crops are treated and that all residues occur at the maximum level seen in use situations. Tolerances are usually set at the limit of analytical detection when residues are not expected to occur. For instance, fruit trees sprayed during dormancy with a product that degrades before fruit are formed hence such tolerances in the fruit are meaningless. Therefore, TMRC greatly exaggerates pesticide intake. 

Finally, even if most of the pesticides worldwide are used in fruit and vegetable crops, data on pesticide residues in animal products are also essential, taking into account that livestock can be easily exposed to pesticides directly or through residues in their feed. For instance, the 2009 European Union Report revealed the presence of 34 different pesticides in animal products [115]. Garcfa de Llasera et al. [128] revealed the presence of chlofenvinphos and chlorpyrifos in liver samples, whereas a-endosnlfan, endosulfan sulfate, and dichloran have been reported in pork and lamb samples (<10 pg/kg) [129]. Bolafios et al. [130] studied the occurrence of organochlorine pesticides and polychlorinated biphenyls in chicken eggs. Benzene hexachloride and 28 polychlorinated biphenyl were detected in only one of the 30 samples at concentrations of 15 and 10 ng/g, respectively. However, five samples also contained traces of OC and PCB residues, even if at concentration levels below the limit of quantification. Einally, a-endosulfan and P-endosulfan were found in commercial milk-based infant formulas at concentration levels from 1.18 to 5.03 pg/kg [35]. The same study also showed the presence of fenitrothion, chlorpyrifos ethyl, and bifenthrin at maximum concentrations of 0.23,1.30, and 0.68 pg/kg, respectively. 

---