Paragraph 1 Purpose and scope

The method described below enables the presence of residues of biphenyl, 2-hydroxybiphenyl (orthophenylphenol) or sodium biphenyl-2-yl oxide (sodium orthophenylphenate) in the peel of citrus fruit to be detected. The sensitivity limit of this method, in absolute terms, is approximately 5 μg. for biphenyl and 1 μg. for 2-hydroxybiphenyl or sodium biphenyl-2-yl oxide, which is the equivalent of 5 mg. of biphenyl and 1 mg. of 2-hydroxybiphenyl respectively in the peel of 1 kg. of citrus fruit.