Residue Reviews / Ruckstands-Berichte: Residue of Pesticides and Other Foreign Chemicals in Foods and Feeds / Ruckstande von Pesticiden und anderen Fremdstoffen in Nahrungs- und Futtermitteln

133 Pages·1969·6.87 MB·English

by  Francis A. Gunther (eds.), Francis A. Gunther (auth.)

RESIDUE REVIEWS
VOLUME 28
RESIDUE REVIEWS
Residues of Pesticides and Other
Foreign Chemicals in Foods and Feeds
RUCKSTANDS-BERICHTE
Riickstande von Pesticiden und anderen
Fremdstoffen in Nahrungs- und Futtermitteln
Edited by
FRANCIS A. GUNTHER
Riverside, California
ADVISORY BOARD
F. BAil, Berlin, Germany· F. BRO-RAsMUSSEN, Copenhagen, Denmark
J. W. COOK, Washington, D.C. • D. G. CROSBY, Davis, California
S. DORMAL-VAN DEN BRUEL, Bruxelles, Belgium
C. L. DUNN, Wilmington, Delaware • H. FREHSE, Leverkusen-Bayerwerk, Germany
J. C. GAGE, Macclesfield, England· H. GEISSBUm.ER, Stein AG, Switzerland
S. A. HALL, Beltsville, Maryland • T. H. HARRIS, Bethesda, Maryland
L. W. HAZLETON, Falls Church, Virginia • H. HURTIG, Ottawa, Canada
O. R. KLIMMER, Bonn, Germany • G. K. KOHN, Richmond, California
H. F. LINSKENS, Nijmegen, The Netherlands· H. MAIER-BODE, Bonn, Germany
N. N. MELNIKOV, Moscow, U.S.S.R. • R. MESTRES, Montpellier, France
P. DE PIETRI-TONELLI, Milano, Italy· R. TRUHAUT, Paris, France
VOLUME 28
SPRINGER-VERLAG
BERLIN • HEIDELBERG • NEW YORK
1969
All rights reserved. No part of this book may be translated or reproduced in
any form without written permission from Springer-Verlag.
ISBN-13: 978-1-4615-8454-4 e-ISBN-13: 978-1-4615-8452-0
DOT: 10.1007/978-1-4615-8452-0
© 1969 by Springer-Verlag New York Inc.
Softcover reprint ofthe hardcover 1s t edition 1969
Library of Congress Catalog Card Number 62-18595.
The use of general descriptive names, trades names, trade marks, etc. in this
publication, even if the former are not especially identified, is not to be
taken as a sign that such names, as understood by the Trade Marks and
Merchandise Marks Act, may accordingly be used freely by anyone.
Title No. 6631
Preface
That residues of pesticide and other "foreign" chemicals in food-
stuffs are of concern to everyone everywhere is amply attested by the
reception accorded previOUS volumes of "Residue Reviews" and by
the gratifying enthusiasm, sincerity, and efforts shown by all the in-
dividuals from whom manuscripts have been solicited. Despite much
propaganda to the contrary, there can never be any serious question
that pest-control chemicals and food-additive chemicals are essential
to adequate food production, manufacture, marketing, and storage, yet
without continuing surveillance and intelligent control some of those
that persist in our foodstuffs could at times conceivably endanger the
public health. Ensuring safety-in-use of these many chemicals is a
dynamic challenge, for established ones are continually being dis-
placed by newly developed ones more acceptable to food tech-
nologists, pharmacologists, toxicologists, and changing pest-control
requirements in progressive food-producing economies.
These matters are of genuine concern to increasing numbers of
governmental agencies and legislative bodies around the world, for
some of these chemicals have resulted in a few mishaps from improper
use. Adequate safety-in-use evaluations of any of these chemicals per-
sisting into our foodstuffs are not simple matters, and they incorporate
the considered judgments of many individuals highly trained in a
variety of complex biological, chemical, food technolOgical, medical,
pharmacological, and toxicological disciplines.
It is hoped that "Residue Reviews" will- continue to serve as an
integrating factor both in focusing attention upon those many residue
matters requiring further attention and in collating for variously trained
readers present knowledge in specific important areas of residue and
related endeavors; no other single publication attempts to serve these
broad purposes. The contents of this and previous volumes of "Residue
Reviews" illustrate these objectives. Since manuscripts are published
in the order in which they are received in final form, it may seem that
some important aspects of residue analytical chemistry, biochemistry,
human and animal medicine, legislation, pharmacology, physiology,
regulation, and toxicology are being neglected; to the contrary, these
apparent omissions are recognized, and some pertinent manuscripts
are in preparation. However, the field is so large and the interests in it
are so varied that the editor and the Advisory Board earnestly solicit
suggestions of topics and authors to help make this international book-
series even more useful and informative.
"Residue Reviews" attempts to provide concise, critical reviews of
timely advances, philosophy, and significant areas of accomplished or
needed endeavor in the total field of residues of these chemicals in
foods, in feeds, and in transformed food products. These reviews are
either general or specific, but properly they may lie in the domains of
analytical chemistry and its methodology, biochemistry, human and
animal medicine, legislation, pharmacology, physiology, regulation,
and toxicology; certain affairs in the realm of food technology con-
cerned specifically with pesticide and other food-additive problems
are also appropriate subject matter. The justification for the prepara-
tion of any review for this book-series is that it deals with some aspect
of the many real problems arising from the presence of residues of
"foreign" chemicals in foodstuffs. Thus, manuscripts may encompass
those matters, in any country, which are involved in allowing pesticide
and other plant-protecting chemicals to be used safely in producing,
storing, and shipping crops. Added plant or animal pest-control chem-
icals or their metabolites that may persist into meat and other edible
animal products (milk and milk products, eggs, etc.) are also residues
and are within this scope. The so-called food additives (substances
deliberately added to foods for flavor, odor, appearance, etc., as well
as those inadvertently added during manufacture, packaging, distribu-
tion, storage, etc.) are also considered suitable review material.
Manuscripts are normally contributed by invitation, and may be in
English, French, or German. Preliminary communication with the
editor is necessary before volunteered reviews are submitted in manu-
script form.
Department of Entomology F.A.C.
University of California
Riverside, California
May 28,1969
Table of Contents
Insecticide residues in California citrus fruits and products
By F. A. Gunther.................................... 1
Subject Index ............................................ 121
Manuscripts in Press ...................................... 128
Insecticide residues in California
citrus fruits and products*
By
FRANCIS A. GUNTHER\)\)
Contents
I. Introduction ................................................. 2
II. Residue legislation ............................................ 6
III. Tolerances .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
a) Establishment of tolerances .................................. 7
b) Pertinent insecticide tolerances for citrus fruits .................. 9
IV. Generalized insecticide residue behavior on and in citrus fruits ....... , 14
a) Degradation and persistence curves ........................... 15
b) Established persistence curves ................................ 34
c) Residue half-life concept .................................... 34
d) Uses of half-lives and persistence curves ........................ 39
e) Effects of variety on residues ................................. 41
V. Insecticide residues in citrus products ............................. 42
a) Citrus juices .............................................. 42
b) Laboratory-prepared citrus pulp cattle feed ..................... 47
c) Citrus oils ................................................ 52
d) Orange marmalade ......................................... 57
e) Dried and candied orange rind ............................... 58
VI. Insecticide residue removal by washing ........................... 58
VII. Systemic insecticides as residues ................................. 59
VIII. Some market survey insecticide residue data ....................... 64
a) The French program ....................................... 64
b) The California-Arizona Citrus League program .................. 64
IX. Multiple residue methods for citrus fruits .......................... 69
X. Developmental citrus residue-analytical methodology with fresh fruits.. 74
a) Presampling considerations .................................. 74
b) Sampling procedure ........................................ 76
c) Storage of fresh samples ..................................... 78
d) Processing of samples ...................................... 79
e) Storage of extractives ....................................... 92
f) The analysis .............................................. 93
• Presented in partial and summary form at the International Citrus Sym-
posium, 19 March 1968, Riverside, California: see GUNTHER and WESTLAKE
(1968) in "References" section .
•• Department of Entomology, University of California, Riverside.
1
2 F. A. GUNTHER
XI. Miscellaneous aspects and conclusions ............................ 96
a) Current insecticide dosages in California ....................... 99
b) Adequate developmental, surveillance, and
mOnitoring programs for pesticide residues ...................... 99
c) Insecticide metabolites and other alteration products in citrus fruits .. 101
d) Citrus insecticides in the grove environment ..................... 102
e) Deposition and persistence of insecticides on leaves versus fruits . . .. 106
Summary ......................................................... III
Resume .......................................................... 112
Zusammenfassung .................................................. 113
References ........................................................ 114
I. Introduction
Prior to about 1945 it was not realized that spray and dust deposits
of most organic insecticidal l chemicals penetrated, in the field, into
subsurface regions of sprayed citrus fruits, even though they were
generally nonsystemic in action, as with some of the DN compounds
and rotenone. Also, emphasis on «residues" (deposits) prior to this
same time was on correlations with pest-control efficacy rather than on
safe consumption of the treated commodity, so that initial deposits and
aged deposits were most often obtained as weight of insecticide per
unit areas of leaf (foliage) tissue 2 rather than on and in mature fruits,
as with sulfur, lime-sulfur, and lead arsenate, because insect popula-
tions were usually evaluated on leaves or twigs rather than on fruits.
In connection with the field performance of DDT and other new in-
secticides against insects and mites in citriculture, however, it was
realized shortly after 1940 that the slow disappearance or attenuation
from leaves of these (DDT) surface deposits and effective residues from
organic pesticides signified at least partial penetration into subsurface
tissues (GUNTHER 1946 and GUNTHER et al. 1946). It was also im-
mediately recognized (BOYCE 1946) that pesticides penetrating into
leaf tissues would probably also penetrate into fruit tissues, and that
these penetrated residues in citrus fruits, for example, could conceiv-
ably constitute a new type of hazard to the consuming public. Atten-
tion was therefore turned immediately to fruits and other edible plant
parts as the residue analytical substrates, and correlations of deposits
and residues with biological performance became of secondary im-
portance as the pharmacological and toxicological significance of per-
sisting and altering «residues" was recognized. Because of laboratory
1 The term "insecticide" often includes those chemicals used for mite control,
or "acaricides." Both types of pest-control agents are considered as insecticides in
the present report. Only the organic insecticides are included. Chemical designa-
tions of insecticides mentioned in text are listed in Table XXXII.
2 See section XI d) for a discussion of deposits and residues expressed as
p.p.m. (weight basis) versus p,g./cm.2 (area basis).
Insecticide residues in citrus fruits 3
convenience and presumed parity of public health significance, these
values were now expressed on a part-per-million basis for all foodstuffs.
Residue chemistry and biochemistry as known today around the
world were therefore conceived within the citrus industry, and the
first true surface and subsurface residue evaluations were made with
mature lemons and oranges in the Department of Entomology, Univer-
sity of Califomia Citrus Experiment Station, Riverside. The term
"residue" was coined to refer to aged and usually penetrated pesticide
chemicals and their in situ alteration products, particularly on and
within the edible parts of treated plants and within animal tissues.
Thus, "deposit" now refers to pesticide chemical initially laid down by
the field treatment, whereas "residue" refers to material on and in the
plant part after the processes of weathering, metabolism, hydrolysis,
penetration, etc., have begun and on (e.g., wool) and in animal parts.
Additionally, chemical so located as still to be available to the pest is
known as an "effective deposit" or "effective residue" depending upon
both its age and its major location with respect to the plant cuticle;
this terminology does not apply to animal tissues (GUNTHER and BLINN
1955, GUNTHER 1962, 1966, and 1968 a).
Federal legislation for control of food quality since 1954 [Public
Law 83-518 et seq. and the Federal Insecticide, Fungicide, and Ro-
denticide Act of 1947 et seq. (HARRIS and CUMMINGS 1964)] has
dictated that tolerance assignments (legally permitted maximum
amounts of residues) and classifications for pesticides on and in raw
agricultural commodities shall be based in part upon particular formu-
lations and particular dosages applied in the field, with specified tim-
ing in relation to harvest or blossoming periods and to numbers and
spacings of multiple applications if required. Acceptable residue in-
formation and tolerance assignments are therefore commonly based
upon extensive biological testing in the field with formulations thought
at that time to be standardized and with dosages that would achieve
the desired pest control. Subsequent significant changes in formula-
tions and recommended dosages require reconsideration by the licens-
ing and registration authorities, with probable reconsideration of
tolerance assignment if dosages or frequencies of applications are
increased or if minimum intervals to harvest are decreased.
Residue information developed in achieving legal commercial use
of a pesticide chemical is therefore felt to represent the maximum
residues that could actually occur in agricultural commodities at har-
vest 3 if the label instructions on the pesticide container were strictly
and consistently followed. Consequently, for every pesticide in every
use on every crop plant there exist often abundant data (usually un-
published) illustrating maximum and average residues that will result
from good agricultural practice. If dosages, timing, formulations, and
8 Ergo, from "good agricultural practice."
4 F.A.GUNTHER
numbers of applications are not appreciably changed after legalized
use is achieved, residues found in "market surveys," "market-basket
studies," residue surveillance 4 programs, and residue monitoring II
programs with a specific crop should reflect the original developmental
data provided those original data were representative of the treated
crop and straddled a harvest period rather than a specific harvest
date, e.g., residues from 15 to 60 days after application versus exactly
30 days after application for mature citrus fruits.
Should the pre- and post-tolerance-assignment residue data differ
markedly - without changes in formulations, dosages, numbers of
applications, or timing - the major causes to be suspect are changes in
the residue analytical methodology or in the adequacy of the sampling
for either the initial or the monitoring program. In general, residue
analytical methodology is steadily improving in both quality and
quantitative reliability and more incisive data would be expected today
than were achievable 10 to 20 years ago, especially in terms of prob-
able metabolites included in the "apparent" residue value; on the other
hand, developmental residue data are usually obtained from extrava-
gantly large field samples and number of replicates to represent the
crop in the field, whereas monitoring and other quality-assurance data
are often from statistically meager samples taken somewhere between
field and consumer, often at the end of the packing house line with
citrus fruits. In some important instances, earlier and current analytical
procedures can be compared for reliability, but it is not easily possible
to correlate a field sampling program with the usual market sampling
program; the former presumably establishes a range of values en-
compassing the mean or average residue load from the field applica-
tion, whereas the latter ideally should demonstrate the maximum
residue present in a shipment, a carload, a lot,a carton, etc. Some
guidelines for field-sampling programs have been adequately estab-
lished for various crops; how to sample in a postharvest residue sur-
veillance or monitoring program is still a matter of empirical judgment
influenced in part by the time available to the sampler, but mostly by
the economics of purchasing the samples, the nature and size of the
crop unit on the market, the size of the lot involved, sample storage
space available to the residue laboratory, the grinding and extraction
equipment available in the laboratory, and others. Over a long enough
period, the continuing "market-basket survey" initiated by the U.S.
Food and Drug Administration is undoubtedly the most realistic ap-
proach to this problem. As has been shown (DE Vos 1968), taking half
a dozen fruits from a carton or market display is not a realistic answer
4 Examining in a suspect area or situation, usually in the field but often in the
wholesale market; guided samples.
II Examining at random, usually with market or wholesale samples; random
samples.