Confusion of identification of o,p'-Kelthane as heptachlor in orange rind extractives.

CONCLUSIONS: Both the glc and the tlc data prove that the unknown compound in the rind of Kelthane-treated oranges was not heptachlor. While the characterization is not absolutely conclusive, there can be no reasonable doubt that it iso,p'-Kelthane, known to be present in technical grade Kelthane.Other workers, using glc, reportedp,p'- ando,p'-Kelthane in the ratio of 100∶1 in 21 market fruit samples from different areas of Southern California. By analogy with DDT, if technical grade Kelthane is assumed to contain up to 20% of theo,p'-isomer this ratio found on fruits treated months previously means that on and in oranges theo,p'-isomer has much the longer half-life (RL50) of the two isomers. On the other hand, approximately equal half-lives are indicated for the two isomers in soil.This brief study emphasizes the need for checking on gas chromatographic data by a more specific method and clearly demonstrates again that improper interpretation of data may be avoided by using at least two columns possessing different retention characteristics for the compounds of interest.