oxygen, hydrogen, deuterium, nitrogen, chlorine, carbon dioxide, nitrogen oxide, ethylene, ozone, arsine, stibine (13). With the permeation tube method, sulfur dioxide, nitrogen dioxide, propane, and butane standards have been successfully prepared in ppm and in ppb concentration ranges (14,15). The saturation method has been used to prepare gaseous solutions of bromine, hydrogen chloride, hydrogen cyanide, monoethanolamine, at relatively high concentration level (12); sulfur dioxide in the concentration range 1.2 X 10-j-1.5 x 10-4 M (11) (the carrier gas used was nitrogen, which passed through two 2-1. thermostated glass bottles put in series, containing sulfuric acid added with some sodium sulfite); hydrochloric acid and ammonia (I). There are three major differences among these methods. The first difference is related t o the reserve of the gaseous reagent. The reserve is very high with the permeation tube method: the composition of the gas mixture is not influenced by the consumption of the gaseous reagent, until the enclosed liquified gas is nearly exhausted, i.e., after months (14, 15). With the electrolytic enrichment, the reserve should also be high (13). The question as to how to make the reserve high with the saturation method has been previously discussed in this paper. The second difference lays on the relation between the composition of the gas mixture and the inert gas flow rate. With the saturation method, the composition is independent of the gas flow rate. The method permits both a wide range of gas flow rate and the delivery of very small volumes of GSS (and of very small quantities of gaseous reagent) at will and easily (Z, 2 ) . On the contrary, with the other two methods,
the composition is strongly dependent on the gas flow rate and accurate gas flow rate measurement and maintenance are necessary (with the electrolytic method accurate electric current measurement and maintenance are also necessary). Variation of the composition of the gas mixture is obtained changing the composition of the mother solution, with the saturation method. More simply, with the permeation tube method, changing the gas flow rate (with the electrolytic method, also changing the electric current); but, especially with high values of gas flow rate (and low values of electric current) difficulties and errors arise (13). The third difference arises from the time necessary to obtain a constant composition of the gaseous mixture, following a non-use period of the apparatus. With the saturation method the composition is unaffected by every sort of non-use period (1, 2). With the other two methods, a certain time, although short, is necessary to reach steady conditions between the inert gas flow rate and the gaseous reagent generation rate. Moreover, any interruption of the gaseous flow, or variation of its rate (and of the electric current) is a source of troubles and errors. The comparison of the performance differences among the three methods is favorable to the saturation method for its simplicity, independence of gas flow rate, and immediate availability a t any time.
RECEIVED for review July 31, 1972. Accepted October 10, 1972. Work supported in part by a grant from the Consiglio Nazionale delle Ricerche, Rome, Italy.
NOTES
Identification of Flame Retardant Textile Finishes by Pyrolysis -Gas Chromatography James F. Cope’ West Point Pepperell Research Center, Shawmut, Ala. 36876
THE STUDY OF FLAME RETARDANT chemicals currently constitutes a very active area of textile research. A wide variety of reagents has been demonstrated to reduce fabric flammability. Many, if not most, of the more successful of these are phosphorus-containing compounds ( I ) .
This note presents a rapid and straightforward technique for the identification of selected examples of these phosphorus derivatives on fabric. EXPERIMENTAL
Present address, Phillips Fibers Technical Center, Greenville, S.C.
All analyses were performed on a Tracor MicroTek 220 vapor phase chromatograph equipped with the flame photometric detection system developed by Brody and Chaney ( 2 )
( 1 ) John W. Lyons, “The Chemistry and Uses of Fire Retardants,” John Wiley and Sons. New York, N. Y.,1970, pp 29-74.
(2) Sam F. Brody and John E. Chaney, J . Gas Chrornatogr., 4, (2) 42 (1966).
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Figure 1. THPOH reagent
Figure 3. Pyrovatex CP reagent
Figure 2. THPOH on cotton Figure 4. Pyrovatex on cotton and marketed by MicroTek Instruments Corp. A dual pen Westronics MT Recorder was employed permitting simultaneous readout of the flame ionization and flame photometric responses; only the photometric response is reported here. Analyses were carried out on a six-foot, stainless steel column packed with 5 OV-1 silicone on 60/80 Chromosorb WAW. Stainless steel columns are not normally recommended for phosphorus analysis, but no apparent difficulty was encountered in this case. Temperature programming from 50 to 180 OC at lO"/minute was applied with an initial hold of one minute and a final hold of four minutes. Total analysis time, including cool down to the initial temperature, was approximately 35 minutes. Pyrolyses were carried out with a Hamilton Multi Purpose Sampling System (Hamilton Co., Whittier, Calif.). The furnace area was maintained at 400 "C. Solid samples were pyrolyzed in small aluminum boats while liquid samples were decomposed in fired quartz tubes packed with quartz wool. A continuous helium flow of 40 rnl per minute was maintained over the samples during pyrolysis.
N o preparation of samples prior to analysis was performed except in the case of tetrakis(hydroxymethy1)phosphonium hydroxide (THPOH) which was prepared by treatment of tetrakis(hydroxymethy1)phosphonium chloride (Hooker Chemical Corp., Niagara Falls, N.Y.) (THPC) with methanolic NaOH as described in the literature ( 3 , 4 ) . It should be noted at this point that there is some conjecture as to the composition of the product derived from the reaction of THPC with NaOH (5, 6). Use of THPOH in this paper does not constitute an identification of a sole product, but simply refers to the mixture produced in that reaction. (3) Wilson A. Reeves, George L. Drake, Jr., John V. Beninate, and Rita M. Perkins, Textile Chem. Color., 1 (17), 365 (1969). (4) John V. Beninate, Eileen K. Boylston, George L. Drake, Jr., and Wilson A. Reeves, Textile Industries, Nov., 1967, p 110. ( 5 ) M. Grayson, J. Amer. Chem. SOC.,85,753 (1963). (6) W. J. Vullo, J. Org. Chem., 33, 3665 (1968).
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Figure 5. Tris(2,3-dibromopropyl)phosphate reagent
4
L
Lb
Figure 7. THPOH on 80/20 blend of cotton/Nomex
Figure 6. Tris(2,3-dibromopropyl)phosphate on polyester
RESULTS AND DISCUSSION
Figures 1 and 2 show the phosphorus response pyrograms for THPOH and cotton fabric treated with the reagent via the ammonia process (3). Figures 3 and 4 are the pyrograms for Pyrovatex CP (Ciba-Geigy Corp., Forest Park, Ga.), [thought to be N-methylol dimethyl phosphonopropionamide (7)] and for Pyrovatex o n all cotton fabric. Figures 5 and 6 show the phosphorus pyrograms of Apex 462-5,2,3-dibromopropyl phosphate, (Apex Chemical Co., Inc., Elizabethport, N.J.) as reagent and applied to polyester fabric.
THPOH and Pyrovatex CP are fiber reactive agents when applied to cellulosics and as expected, the pyrograms of the agents on fabric and when pyrolyzed neat show little similarity. The 2,3-dibromopropyl phosphate, on the other hand, does not react with polyester fiber, to which it is most frequently applied. As a result, one observes that the principal peaks in the pyrogram of the retardant on polyester are also present in the pyrogram of the reagent alone, although the chromatogram in the former case is much simpler. Each of the compounds investigated provides a unique and reproducible pyrogram under the stated conditions. It appears, however, that the fabric system to which the reagent is applied has considerable influence on the shape of the fingerprint. Thus Figure 2 could be compared with Figure 7 in which THPOH is applied to a n 80,’20 blend of cottoniNomex (Du Pont). Most of the peaks remain, but the relative intensities have been drastically altered. Even greater changes have been observed with other blends (8). So, the pyrograms obtained are characteristic not only of the flame retardant, but also of the particular fabric to which they xt:applied.
(7) R. Aenishanslin, C. Guth, P. Hofmann, A. Maeder, and H. Nackbur, Textile Res. J . , 39,375 (1969).
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ACKNOWLEDGMENT
The author thanks Alice Nevels for preparation of many of the fabric samples used in this work.
RECEIVED for review June 12, 1972. Accepted October 26, 1972. (8) James F. Cope, West Point Pepperell Research Center, Shawmut, Ala., unpublished results, 1971.
