Lectures on Gas Chromatography 1966: Based in Part on Lectures Presented at the Eighth Annual Gas Chromatography Institute, Held at Canisius College

225 Pages·1967·6.49 MB·English

by  Royce E. Johnson (auth.)

Lectures on
GAS CHROMATOGRAPHY
1966
Lectures on
GAS CHROMATOGRAPHY
1966
Based in Part on Lectures Presented at the Eighth Annual
Gas Chromatography Institute, Held at Canisius College
Edited by
Leonard R. Mattick
Food Research Laboratory
New York State Agricultural Experiment Station
Cornell University, Geneva, New York
and
Herman A. Szymanski
Department of Chemistry
Canisius College, Buffalo, New York
~
PLENUM PRESS . NEW YORK . 1967
Library of Congress Catalog Card Number 61-15520
ISBN 978-1 -4684-9 104-3 ISBN 978-1-4684-9102-9 (eBook)
DOl 10.1007/978-1-4684-9102-9
© 1967 Plenum Press
Softcover reprint o/the hardcover 1st edition 1967
A Division of Plenum Publishing Corporation
227 West 17 Street, New York,N. Y.100ll
All rights reserved
No part of this publication may be reproduced in any
form without written permission from the publisher
FOREWORD
Many of the papers in this volume are baSed on lectures
presented at the Eighth Annual Gas Chromatography Institute
held at Canisius College, Buffalo, New York, April 11-15,
1966, and at the Pesticide Residue Analysis Workshop con
ducted at the Institute by Leonard R. Mattick. These lectures
are here supplemented by several papers prepared, at the
invitation of the editors, by authors whose work, though not
presented at the Institute, helps to illustrate current progress
in gas chromatography.
v
CONTENTS
Characteristics of the Phosphate Sensitive Sodium Sulfate
Modified Hydrogen Flame Ionization Detector
Royce E. Johnson. . . . . . . . . . . . . . . . . . . . . . . . 1
Analysis of Organophosphorus and Organic Iodine Resi-
dues by Microwave Powered Emission Spec
trometry
C. A. Bache and D. J. Lisk. ......... . 17
Gas Chromatography of Amino Acids
William J. McBride and Jack D. Klingman 25
Recent Advances in Applications of the Microcoulometric
Titrating System
John A. Stamm. • • • • • • • • • • • • • • • . • . • • • • • • • 55
Automatic Integrators and Gas Chromatography
Daniel M. Marmion . • . • • • • • • • . . • . • • . • . • . • 63
Measurement of Trace Amounts of Inert Gases in Blood
by Gas Chromatography
Francis J. Klocke. . . . . . . . . . . . . . . • • • • • • • • .. 75
Gas Chromatography of Vitamin B6 and Other Vitamins
Walter Korytnyk ••••••••.••.•••.••.•.••• 89
Dual Channel Gas Chromatography
Ernest J. Bonelli. • • . . • . • . . . . • . • . . . . . . 105
Analytical Methods for Pesticides
H. P. Burchfield. • • . • . . . . . . . . . . . . • . . . . . .. 121
vii
viii CONTENTS
A Modified Hydrogen Flame-Ionization Detector, Highly
Sensitive and Selective for Phosphates
R. V. Hoffman. . . . . . . . . . . . . . . . . . . . . . . . .. 137
Galvanic-Coulometric Detectors in Gas Chromatography
Paul Hersch. . . . . . . . . . . . . . . . . . . . . . . . . .. 149
Analysis of Some Nonprotein Amino Acids by Gas Chro
matography
K. Blau ., . . . . . . . . . . . . . . . . . . . . . . . . . . .. 183
Application of Specific Detectors in Microanalysis by
Gas Chromatography
A. Karmen . . . . . . . . . . . . . . . . . . . . . . . . . . .. 211
Index. ................. _ . . . . . . . . . . . . . . .. 225
Characteristics of the Phosphate
Sensitive Sodium Sulfate Modified
Hydrogen Flame Ionization Detector
Royce E. Johnson
Barber-Colman Company
Rock ford, Illinoi s
Highly selective and sensitive gas chromatograph ioniza
tion detectors have become indispensable in this age of pesti
cides and herbicides. The electron attachment detector, for
example, has aided chemical manufacturers in developing
many effective, safe-to-use pesticides. Regulatory agencies
have found the electron attachment detector indispensable for
their pesticide residue examinations.
After several years of searching for a selective and
equally sensitive detector for phosphated pesticides, one has
been reported upon by Giuffrida [1] of the United States Food
and Drug Administration Department of Chemistry. Her
report in the n Journal of Official Agricultural Chemists n de
scribes this detector and lucidly presents the results of valu
able original exploratory work with it.
Giuffrida found that various hydrogen flame detectors,
when modified, gave comparable results for organophosphate
pesticides. Her report contains information on the essential
characteristics of the detector and the sodium salt modifica
tion thereof. It also contains information on the relation of
hydrogen flow to response. Her table of relative retention
1
2 R. E. JOHNSON
times on a DC-200 column for 21 phosphated pesticides is
also a contribution to work in this field.
The present discussion is more concerned with operational
characteristics of the detector and methodology than it is
with the columns. Characteristics of the sodium salt elec
trode modification and the conventional flame detectors are
compared to some extent. This will assist a flame detector
operator when he first uses the sodium salt coated electrode
and. it is hoped. also will be helpful to those using the sodium
thermionic emission detector without prior experience with
the flame detector. Flame detector theory is reviewed and
several chromatograms are shown in this comparison.
APPARATUS
For this report a helically coiled platinum wire electrode.
as used by Giuffrida. was mounted on the burner tip of a
Barber-Colman Company Model 5121 Hydrogen Flame Ioni
zation Detector. The detector was placed in the Model 5360
Pesticide Analyzer instead of the electron attachment de
tector normally supplied with this instrument. A 6 ft by 4 mm
i.d. coiled glass column with 5% SF-96 on 90-100 mesh ABS
support was used.
A view of the detector base with the sodium salt coated
platinum electrode on the burner tube is shown in Fig. 1. The
chimney with its side arms for ignition loop and anode sup
port and electrical connections has been removed for the
photograph. but removal is unnecessary for installation of the
electrode. Effluent and hydrogen burn as the mixture flows
from the burner tube up through the helix.
GENERAL WEORY
Ionization takes place in the combustion zone. In the hydro
gen flame detector. ionization efficiency is between 0.0005
and 0.001%. Only the few molecules of the sample that acquire
PHOSPHA TE SENSITIVE IONIZATION DETECTOR 3
Fig. 1. Hydrogen flame ionization detector base with sodium sulfate coated electrode
on flame tube tip.
sufficient energy in the flame become ionized f,3j. As a
first approximation for compounds of carbon and hydrogen,
the magnitude of ionized current is proportional to the number
of carbon atoms involved.
Organic materials containing oxygen or halogens are
ionized in a hydrogen flame even less efficiently. Sternberg
[2] relates the decrease in response quantitatively to the num
ber and position of halogen and oxygen atoms in the molecules.
For the hydrogen flame ionization detector, Sternberg
reported contributions in units of ionization for various func
tional groups and molecular bondings. In olefinic, acetylenic,
carbonyl, and nitrile molecular structures, the carbon number
contributions are 0.95, 1.2, 0.0, and 0.3, respectively. Oxygen
contributions range from -1.0 in ether through -0.6 for alco
hols to -0.25 for tertiary alcohols. Chlorine contributions
range from -0.12 to +0.05 in aliphatic and olefinic compounds.
The sodium salt coated electrode in the hydrogen flame
ionization detector superimposes an additional source of ions
4 R. E. JOHNSON
on the basic or background hydrogen flame ionization. The
base or standing current when the sodium electrode is used
is so much higher than the base current for the flame that
the latter may be practically negligible in comparison. This
relation exists with normal column bleed levels. In the
modified flame ionization detector, the ionizing efficiency of
the thermionic sodium atmosphel'e for typical phosphated
pesticides is between two and three orders of magnitude
higher than that of the hydrogen flame ionization detector.
Giuffrida [1] reports that for a compound containing 6 chlorine
atoms, the response was enhanced about 2000% by the sodium
salt coating.
For hydrocarbons the ionizing efficiency of the two de
tectors is approximately the same for equal hydrogen combus
tion rates; however, the sodium electrode detector requires
somewhat higher hydrogen flow rate.
PERFORMANCE
In the typical hydrogen flame ionization detector, hydro
gen flow in excess of the optimum gives less response to
organic materials, as is shown in Fig. 2, where the materials
consist of stationary phase vapors. The extent to which the
standing current decreases as the hydrogen flow exceeds the
optimum varies with conditions. If there are organic vapors
in the hydrogen, whether coming from the cylinder or the
plumbing, an increased flow will carry more combustibles
per second to the flame. Excessive contamination in the
hydrogen will obliterate the valley so that the standing cur
rent will increase continuously with the hydrogen flow rate.
It is to be noted that at some flow (48 to 53 ml/min for column
flows in Fig. 2) sufficient heat is liberated to cause emission
of electrons, as for example, the increase in standing current
occurring for conditions in Fig. 2 at about 53 ml/min with a
column flow of 57 ml/min. Observation of the platinum anode
loop reveals increasing incandescence as the hydrogen flow
is increased beyond that at the bottom of the valley in the