Letter | Published:

Reduction of Parathion induced by Light


WHILE investigating the decomposition of parathion (O,O-diethyl-O-p-nitrophenylphosphorothionate) I was able to confirm the findings of Ketelaar1 on the specific action of Cu2+-ions in catalysing the hydrolysis leading to p-nitrophenol. Other metal ions are ineffective, and the catalytic action of copper can be suppressed by various chelating agents2. The experiments were carried out at room temperature in a barbiturate milieu at pH 8.0 and lasted for more than four weeks. Change in concentration of parathion with a modified polarographic method was followed, and this permitted the estimation of parathion and simultaneously of the p-nitrophenol formed. In certain instances however, in solutions not containing the catalyst, a significant decrease of the polarographic wave of parathion was observed though the corresponding appearance of p-nitrophenol was not detected. Although in publications dealing with the degradation of parathion4 there is no allusion to the possibility of a spontaneous reduction, I have shown it to be induced by light.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Ketelaar, J. A. A., Nature, 177, 392 (1956).

  2. 2

    Sándi, E., Paper read at the 22nd Meeting of the Hungarian Physiological Society, Debrecen, July 1956 (in the press).

  3. 3

    Josepovits, G., and G.-Privitzer, K., Magy. Kém. F., 59, 161 (1953).

  4. 4

    Gar, K. A., Melnikov, N. N., and Mandelbaum, J. A., Dokl., 94, 729 (1954). Payton, J., Nature, 171, 355 (1953).

  5. 5

    Averell, P. R., and Norris, M. V., Anal. Chem., 20, 753 (1948). Clifford, P. A., J. Assoc. Agric. Chem., 34, 533 (1951).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.