Gas Chromatographic Analysis

770 Pages·1972·14.17 MB·English

by  Gunter Zweig, Joseph Sherma and Gunter Zweig (Auth.)

Volume I
PRINCIPLES, METHODS, AND GENERAL APPLICATIONS
Volume II
INSECTICIDES
Volume III
FUNGICIDES, NEMATICIDES AND SOIL FUMIGANTS,
RODENTICIDES, AND FOOD AND FEED ADDITIVES
Volume IV
HERBICIDES
Volume V
ADDITIONAL PRINCIPLES AND METHODS OF ANALYSIS
Volume VI
GAS CHROMATOGRAPHIC ANALYSIS
Analytical Methods
PESTICIDES AND
for
PLANT GROWTH
REGULATORS
Edited by
GUNTER ZWEIG
Life Sciences Division, Syracuse University Research Corporation
Syracuse, New York
Volume VI G AS
CHROMATOGRAPHIC
ANALYSIS
by
GUNTER ZWEIG and JOSEPH SHERMA
Department of Chemistry
Lafayette College
Easton, Pennsylvania
With contributions by others
ACADEMIC PRESS New York and London 1972
COPYRIGHT © 1972, BY ACADEMIC PRESS, INC.
ALL RIGHTS RESERVED
NO PART OF THIS BOOK MAY BE REPRODUCED IN ANY FORM,
BY PHOTOSTAT, MICROFILM, RETRIEVAL SYSTEM, OR ANY
OTHER MEANS, WITHOUT WRITTEN PERMISSION FROM
THE PUBLISHERS.
ACADEMIC PRESS, INC.
Ill Fifth Avenue, New York, New York 10003
United Kingdom Edition published by
ACADEMIC PRESS, INC. (LONDON) LTD.
24/28 Oval Road, London NW1
LIBRARY OF CONGRESS CATALOG CARD NUMBER: 63-16560
PRINTED IN THE UNITED STATES OF AMERICA
Contributors to Volume VI
Numbers in parentheses refer to the pages on which the authors' contributions begin.
J. E. BARNEY (408), Stauffer Chemical Company, Western Research Cen-
ter, Richmond, California
Lois ANN BEAVER (39), Food and Drug Administration, Buffalo, New
York
J. E. BOYD (357, 418, 493), American Cyanamid, Agricultural Research
Center, Princeton, New Jersey
R. W. BUXTON (519, 672), Stauffer Chemical Company, Western Re-
search Center, Richmond, California
JOHN CROSSLEY (556), Ortho Division, Chevron Chemical Company,
Richmond, California
J. E. DEVINE (692), Lake Ontario Environmental Laboratory, Ν. Y. State
Univ. College, Oswego, N.Y.
W. Y. JA (408, 519, 644, 672, 686, 698, 708), Stauffer Chemical Com-
pany, Western Research Center, Richmond, California
J. B. LEARY (350), Ortho Division, Chevron Chemical Company, Rich-
mond, California
J. C. MCKAY (519, 672), Stauffer Chemical Company, Western Research
Center, Richmond, California
N. R. PASARELA (107), American Cyanamid, Agricultural Research Cen-
ter, Princeton, New Jersey
G. G. PATCHETT (644, 668, 686, 698, 708), Stauffer Chemical Company,
Western Research Center, Richmond, California
SHELL DEVELOPMENT COMPANY (268, 287, 324, 450), Modesto, Cali-
fornia
D. L. SHELMAN (408, 668), Stauffer Chemical Company, Western Re-
search Center, Richmond, California
W. J. SMITH (644, 668, 686, 698, 708), Stauffer Chemical Company,
Western Research Center, Richmond, California
xxiii
Preface
Publication of Volume VI of the treatise previously entitled "Analyt-
ical Methods for Pesticides, Plant Growth Regulators, and Food Additives"
(the title has been abbreviated to "Analytical Methods for Pesticides and
Plant Growth Regulators") is a milestone for several reasons. The contents
of this volume are devoted to a single topic: pesticide analyses by gas
chromatography. We have attempted to compile the most important and
latest information (to 1971) on gas chromatographic analyses from all the
previously described pesticides and plant growth regulators covered in
Volumes I-V. That this attempt has been almost wholly successful is at-
tested to by the large number of chapters comprising this volume (128)
and by the fact that gas chromatographic information was available on al-
most all of the compounds covered in previous volumes with those few ex-
ceptions where this elegant analytical technique could not be applied.
Compounds which have been covered in previous volumes but for which
no gas chromatographic analytical techniques have been described have
been omitted: Coumachlor (Volume III, pp. 185-186); Warfarin (Vol-
ume III, pp. 197-201); Anot (Volume III, pp. 207-208); ethylene glycol
and propylene glycol (Volume III, pp. 217-220); and Zoalene (Volume
III, pp. 221-222).
Following the format of previous volumes, Part I deals with the
more general subjects as, for example, sample preparation, detectors, qual-
itative analyses, and formulation analyses, and includes three chapters on
gas chromatography of different classes of pesticides. The reader is referred
to two excellent chapters by Arthur Bevenue on gas chromatography of
pesticides which appeared in Volumes I and V. Since the electron capture
detector had been thoroughly discussed in these chapters, greater emphasis
has been placed in this volume on the more recently developed detectors,
such as the flame photometric device for sulfur and phosphorus. Specific
applications for the formulation and residue analyses of over one hundred
pesticides are described in great detail, including preparation of various
food and environmental samples for residue determinations. Reagents and
equipment are given only in cases in which special conditions warrant such
inclusion. Reference is made to previous volumes for general information
concerning specific pesticides as well as analytical techniques other than gas
chromatography. Where gas chromatography had been described previously,
only newer techniques have been given in this volume.
No attempt was made to cover the literature completely from 1960
through 1970, but the authors endeavored to choose the most appropriate
analytical methods based on their own experience or those of others who
graciously contributed to this volume either by advice or direct contribu-
xxv
xxvi PREFACE
tion. To acknowledge the help of many friends and colleagues, we would
like to thank especially the residue chemists of the Shell Development Com-
pany in Modesto; the Chemagro Co.; J. B. Leary and John Crossley of
Chevron Chemical Co.; J. E. Barney, R. W. Buxton, J. C. McKay, W. Y.
Ja, G. G. Patchett, D. L. Shelman, and W. J. Smith—all from the Stauffer
Chemical Company in Richmond, California; Dr. John Boyd and N. R.
Pasarela of American Cyanamid, Princeton, New Jersey; and Lois Ann
Beaver of the Food and Drug Administration, Buffalo, New York.
Attention is called to the reader that at the end of this volume a
Cumulative Subject Index will be found covering all six volumes.
"Food Additives" has been eliminated from the title because a sep-
arate, multivolume treatise would now be required to cover the com-
pounds in this rapidly growing area.
We invite the readers of this book to send comments, corrections,
additions, and any other suggestions which we will try to incorporate in
future volumes of this treatise.
GUNTER ZWEIG
JOSEPH SHERMA
Sample Preparation
This chapter contains a general discussion of sample preparation and
handling methods for the gas chromatographic analysis of pesticides. De-
tails of methods applicable to certain classes of pesticides are presented
in Chapters 5, 6, and 7, while other sample preparation procedures in-
volved in the qualitative analysis of pesticides are found in Chapter 3. A
general discussion of extraction and cleanup procedures not necessarily for
samples to be analyzed by gas chromatography was presented in Volume
I of this series (Thornburg, 1963).
I. SAMPLING FOR PESTICIDE RESIDUE ANALYSIS 1
In order that the analytical results have validity in terms of the level
of pesticide contamination, the sample taken for analysis must be random
and representative (Garber, 1963). Randomization involves selection of
sample so that each unit of material in the batch has an equal chance of
being chosen for the extraction and final test. A representative sample has
a proportion of each type of material that is identical with that of the gross
sample from which it was taken. Once collected, the sample must be care-
fully handled and stored to avoid loss (e.g., by volatization) or concentra-
tion of the residue.
Variables to be considered in obtaining a valid sample include the
source of the sample; the size, nature, and stability of the raw commodity;
the method by which the pesticide was applied; intended use of the com-
modity (i.e., how much of a crop is consumed); and variations in the size
and/or density of the crop. Table I shows field sampling methods for vari-
ous types of raw agricultural commodities and Table II methods for pre-
paring collected samples for analysis on a whole basis according to Federal
Food, Drug and Cosmetic Regulation Act 21 CFR 120.1 (j) or on an
edible portion basis.
Processed foods are sampled just prior to final packaging by selecting
three 4 lb samples from the first, middle, and last material being processed.
These are mixed, reduced by quartering to three 2 lb subsamples, and
^uggan (1969); McFarren (1968).
1
2 GAS CHROMATOGRAPHIC ANALYSIS
TABLE I
0
FIELD SAMPLING OF RAW AGRICULTURAL COMMODITIES
Commodity Sampling method
Large fruit trees Take gross sample of about 100 lbs, sampling each tree
in small plot and at least 16 trees from large plot.
Sample all four quadrants of each tree at both inner
and outer levels, selecting the fruit in proportion to its
abundance. Reduce gross sample by mixing and quar-
tering to 25 lbs (see Fig. 1). Subsample by cutting each
fruit in half, mix and quarter the pieces until a 6 lb sam-
ple is obtained. Divide into 3 equal representative por-
tions, label, and freeze. Fruits to be consumed fresh and
whole are analyzed with peel intact. Fruits to be peeled
and processed are peeled before subsampling.
Nut crops Procedures applicable to tree fruits are usually applicable
to nut crops. Remove and discard hulls and shells unless
they are to be used for animal feed. Samples and sub-
samples are not usually frozen.
Small fruits (blueberries, Gross sample of 20 lbs taken from 12-24 sampling stations
currants, grapes, cherries) by two persons picking simultaneously from opposite
sides of the row. Gross sample is reduced as above, and
2 lb subsamples are frozen.
Legumes for food (peas, Peas are hulled. Sample is collected and handled as for
lima beans) small fruit.
Legumes for forage (alfalfa, Forage is cut to normal harvest height and a 1 lb sample
clover, hay) and grain is reaped from each of 24 random sampling stations.
forage (corn, sorghum) The samples are cut into 1-inch lengths, combined,
mixed, and reduced by quartering to a 6 lb sample. If
grain forage is green or wet, freeze final samples.
Grains for food (barley, Collect 24 1 lb samples from the discharge shute of the
oats, wheat) harvester uniformly over the entire plot. Combine and
quarter. Corn is sampled by collecting 5 or 6 dry
mature ears from each of 24 stations in the field ; husks
are stripped off and kernels removed from the cob.
Leafy vegetables (collards, Collect forage normally used for food from 12 to 24
kale, leaf lettuce) sampling stations. Composite samples and reduce by
mixing and quartering. Components in 6 lb samples are
washed, drained, chopped into small pieces, and frozen.
Head crops (cabbage, head Collect 25 heads from each plot and trim to market con-
lettuce, celery) and dition. Quarter heads and combine to produce gross
solanaceous fruits (egg- sample. Reduce sample by cutting each quarter into 1
plant, peppers, tomatoes) inch pieces, mix, quarter, and freeze.
1. SAMPLE PREPARATION 3
TABLE I (continued)
Commodity Sampling method
Cucurbits or vine crops Method similar to head crops. The rind may be removed
(melons and squash) depending upon use of crop. If removed, wash and
quarter as above.
Perennial crops (asparagus, Collect from 12-24 stations. Trim each unit, wash as for
artichokes, rhubarb) market, and chop into small pieces. Mix and reduce by
quartering.
Root crops (beets, carrots, Collect 20-50 lb gross sample from 12-24 stations. Re-
onions, potatoes, radishes) move tops and roots and reduce to one-half by quar-
tering. Sample is then washed free of dirt, chopped
into 1 inch pieces, mixed and quartered, and the final
6 lb sample divided into 3 portions, which are frozen.
1
From McFarren (1968).
frozen. Table III lists certain processed commodities whose preparation
for analysis is specified. In other cases, samples are prepared from the "as
is" product. Concentrates, dehydrated products, etc., are not reconstituted
before analysis. Sampling of produce at the market has been discussed by
Rollins (1963) in Volume I of this series. Sizes of routine and confirma-
tion samples for fruits and vegetables were listed on p. 608 of Volume I.
Bulk agricultural materials (e.g., grains, flour, fertilizers, nuts, dried
milk, beans, seeds) are sampled when bins or elevators are being loaded
or unloaded. Samples are collected at regular intervals during the entire
emptying or filling period. A composite sample of 5 kg is collected from
small bins, trucks, or freight cars using a grain trier or thief. Bags and
barrels are sampled with a smaller thief passing diagonally through the
sack or barrel from one corner at the top to the opposite corner at the
bottom. A recommended sampling schedule is presented in Table IV.
Meat and poultry products are sampled at the packaging plant or
retail market. Soft tissues are passed through a meat grinder about three
times, after which the samples are mixed and quartered. Fish and other
marine products are sampled after they have been landed and sorted. A
longitudinal half of small fish is taken for analysis. For large fish, three
one-inch transverse slices are cut—one from immediately behind the pec-
toral fin, one half way between the pectoral fin and vent, and one imme-
diately behind the vent. The pieces are passed through a food chopper
three times and mixed each time. Shells are removed and discarded from
shellfish.
Milk samples are collected from dairy farms, pasteurizing plants, and
4 GAS CHROMATOGRAPHIC ANALYSIS
TABLE II
PREPARATION OF RAW AGRICULTURAL COMMODITIES"
Preparation6
Commodity Specified in CFR 120.1(j)c Edible portion**
Bananas Remove and discard crown tissue Remove and discard peel ;
and stalk. examine pulp only.
Sweet corn Examine kernels plus cobs ; husks Remove and discard husks and
removed, for some tolerance cob; examine kernels.
regulations.6
Eggs Same as edible portion guide/ Discard shells, examine combined
yolks and whites.
Fish (raw) Same as edible portion guide.e Remove and discard heads, scales,
and guts; examine remainder,
including tails if present.
Fruits (general) Remove and discard stems.
Fruits (stone) Remove and discard stones or pits.
Garlic bulbs Remove and discard roots, stems, Same.
and outer sheaths or husks;
examine garlic cloves only.
Mangoes Remove and discard rind and
stone.
Melons Remove and discard stems. Remove and discard rind, stems,
and seeds.
Nuts, including Remove and discard shells. Same.
peanuts
Oysters, clams Use edible portion guide/ Examine a homogeneous mixture
(raw) of meats and liquors.
Pineapple Remove and discard crowns (top Remove and discard crown and
leaves). flowers (outer protective petals).
Pumpkins Remove and discard rind, stem,
and seeds.
Root crops Use edible portion guide/ Rinse lightly to remove adhering
(general) soil.
Root vegetables, Examine roots and tops separately. Same.
including tops The pesticide residues on either
or with tops part must not exceed tolerance
level. For carrots only, remove
tops and discard, and analyze
roots only.
Shrimp (raw), Use edible portion guide/ Remove and discard heads, tails,
crawfish, and and shells; examine edible meat
similar shell only.
fish
Strawberries Remove and discard caps (hulls). Same.
a
Duggan (1969, Sect. 141.12). Users should check most recent F.D.A. "Pesticide
Analytical Manual" to ensure that changes have not been issued by F.D.A.
6
In all cases, obviously decomposed leaves, berries, etc., are removed.
c
This regulation directs which portion of the commodity is to be discarded and which
portion is to be taken for analysis, in accordance with how most tolerances were established
on the products.
d
Inedible portions are discarded and edible portion only is analyzed.
β
Preparation of these commodities not specified, current policy given.