Sample manipulation and apparatus useful in estimating surface and penetration residues
      of DDT in studies with leaves and fruits

Gunther, F

Sample manipulation and apparatus useful in estimating surface and penetration residues of DDT in studies with leaves and fruits

Author

Francis A. Gunther

Author Affiliations

Francis A. Gunther was Assistant Insect Toxicologist.

Publication Information

Hilgardia 18(6):297-316. DOI:10.3733/hilg.v18n06p297. June 1948.

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Abstract

Abstract does not appear. First page follows.

Introduction

The consequences of DDT applied in the field have been intensively investigated at the University of California Citrus Experiment Station since 1943. Early in this investigation certain instances disclosed that DDT, as it was applied in the field in various experimental formulations, actually penetrated the fruit and leaf tissues. This indicated potential consumer hazards. Therefore, a detailed semiquantitative examination of surface residues and of the extent and degree of penetration resulting from such applications was undertaken.

Materials examined in this program included fruit, and sometimes leaves, from mature apple, avocado, citrus, olive, peach, pear, and plum trees. At the present time a report of the analytical techniques developed empirically from the handling of many thousands of these samples, and a detailed description of some of the apparatus used may be of benefit to other investigators.

(Carter and Hubanks (1946))4 recently presented a brief discussion of apparent “recoveries,” by analytical methods, of DDT added to dried plant material, including apples. Their results agree with those obtained by the techniques developed during the present investigation. Moreover, (Wichmann et al. (1946)) recently have thoroughly discussed the application of three methods for the quantitative determination of DDT as spray residues on fresh fruit, particularly apples and pears. Certain points of similarity between the techniques discussed by Wichmann et al., and those discussed in the present paper will be noted.

It must be emphasized that certain of the manipulative procedures described in this report are only semiquantitative in nature.

Literature Cited

Beier W. E., Edmonds E. J., Wilson C. W., Elliot M. I., Gunther F. A. A method for the quantitative estimation of DDT in plant and/or sulfur-containing materials. Science. 1946. 104:376-77.

Bulger J. W. A photoelectric method for measuring small leaf areas. Jour. Econ. Ent. 1935. 28:76-81.

Carter R. H., Hubanks P. E. Determination of DDT deposits on fruits, vegetables, and vegetation. Assoc. Off. Agr. Chem. Jour. 1946. 29:112-14.

Gunther F. A. Dichlorodiphenyltrichloroethane. I. Solubility in various solvents. Amer. Chem. Soc. Jour. 1945a. 67:189-90. DOI: 10.1021/ja01218a010 [CrossRef]

Gunther F. A. Quantitative estimation of DDT and of DDT spray or dust deposits. Indus. and Engin. Chem., Analyt. Ed. 1945b. 17:149-50. DOI: 10.1021/i560139a008 [CrossRef]

Gunther F. A. Aspects of the chemistry of DDT. Jour. Chem. Ed. 1945c. 22:238-42. Errata. Ibid., p. 279. DOI: 10.1021/ed022p238 [CrossRef]

Gunther F. A., Lindgren D. L., Elliot M. I., LaDue J. P. Persistence of certain DDT deposits under field conditions. Jour. Econ. Ent. 1946. 39:624-27.

Kramer P. J. An improved photoelectric apparatus for measuring leaf areas. Amer. Jour. Bot. 1937. 24:375-76. DOI: 10.2307/2437037 [CrossRef]

Milthorpe F. L. A simplified photoelectric cell method for measuring leaf areas. Australian Inst. Agr. Sci. Jour. 1942. 8:27

Turrell F. M. Tables of surfaces and volumes of spheres and of prolate and oblate spheroids, and spheroidal coefficients. 1946. Berkeley and Los Angeles.: University of California Press. 153p.

Turrell F. M., Waldbauer L. A bibliography on the use of photoelectric cells in plant investigations. Iowa Acad. Sci. Proc. 1935. 42:67-70.

Wichmann H. J., Patterson W. I., Clifford P. A., Klein A. K., Claborn H. V. The determination of DDT as spray residue on fresh fruit. Assoc. Off. Agr. Chem. Jour. 1946. 29:188-218.

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