Gas Chromatographic Analysis of Various M xtures of Compounds Containing Chlorine G. W. WARREN, L. J. PRIESTLEY, Jr., J. F. HASKIN, and V. A. YARBOROUGH Development Department, Union Carbide Chemicals Co., Division o f Union Carbide Corp., South Charle. on,
b Gas chromatographic methods were developed for the analysis of several mixtures of chlorine-containing compounds from laboratory process studies. A chromatographic method was developed for the analysis of unrefined 1,2-dichIoroethane, refined carbon tetrachloride, and chloroform because other instrumental and/or chemical techniques were not applicable. The lower detection limits for chloroform, trichloroethylene, and tetrachloroethylene in carbon tetrachloride are 200, 200, and 500 p.p.m., respectively. The lower detection limits for dichloromethane, 1,l -dichloroethane, 1,2-dichIoroethane, and carbon tetrachloride in chloroform are 50, 200, 400, and 200 p.p.m., respectively. The chromatographic method for the analysis of refined l-chlorobutane requires 12 minutes; the chemical method takes 40 minutes.
T
technique of gas chromatography as developed by James and Martin (3-5) and James and Phillips ( 6 ) has been used for the separation and analysis of various mixtures. I n this laboratory i t has replaced other instrumental and chemical methods which require excessive time. Some of the chromatographic methods developed have been for the analysis of mixtures of chlorine-containing compounds. Other investigators ( 1 , 21 7 , 8) have used the technique to analyze mixtures of halogen-containing compounds. Evans and Tatlom ( I ) investigated organic fluorine compounds; Green ( 2 ) quantitatively analyzed mixtures of chlorofluoromrthanes and carbon tetrachloride; and Perciral (7) analyzed mixtures of fluorocarbons. Chromatographic methods were developed for the analysis of unrefined 1,2-dicliloroetliaiie (ethylene dichloride) to replace a mass spectrometric method; for the analysis of refined chloroform and carbon tetrachloride because other instrumental techniques were not applicable; and for the analysis of refined I-chlorobutane (n-butyl chloride) because of possible application for continuous on-stream gas rhromatographic analysis. The chromatographic method was faster than the chemical method used for routine analyses. HE
w. Va.
En G
ii
A
Retention time, minutes
Figure 1.
Chromatogram of unrefined 1,2-dichloroethane
Column, paraffin on Celite 545, 2 meters X 4.7 mm. minute. Recorder attenuation in parentheses A. 1,1,2,2-Tetrachloroethane (1) 6 . Tetrachloroethylene (1 ) C. 1,l,2-Trichloroethone (1 ) D. Trichloroethylene (1) E. 1,2-DichIoropropane (1)
Table 1.
Temperature, 90' C.
F. G.
H. 1. J.
Flow, 200 cc. of He per
Carbon tetrachloride ( 1 ) 1,2-Dichloroethane (1 6 ) Chloroform (1 ) cis-Dichloroethylene (1 ) frons-Dichioroethylene (1
Analysis of Unrefined 1,2-Dichloroethane
Component Area yG 0.22 trans-Dichloroethylene 0.24 cis-Dichloroethylene Chloroform 0.33 87.6 1,2-Dichloroethane 0.18 Carbon tetrachloride 1.54 1,2-Dichloropropane Trichloroethvlene 0.61 1,1,2-Trichlo"roethane 1.66 Tetrachloroethylene 4 19 1,1,2,2-Tetrachloroethane 3.44 a Based on five determinations. APPARATUS AND PROCEDURE
A Perkin-Elmer Model 154 Vapor Fractometer mas used for all determinations. Liquid samples (0.01 to 0.02 ml.) were introduced with a hypodermic syringe and a 1.6-cm. S o . 27 hypodermic needle through a siliconerubber diaphragm into the carrier gas stream of helium. The detector response was recorded on a Bronn 0- to 10-mv. strip chart recorder. The signal m s attenuated by a knoivii factor to maximize each deflection on the chart paper. The base line was not readjusted, as the signal was attenuated. Areas under the curves were measured with a n Ott compensating polar planimeter. dl1 columns used were 2 meters b y 4.7 mm. in inside diameter. The following parameters were used for each of the methods: 1,Z-Dichloroethane. -4 column of paraffin (Esso household wax) (307,)
ilv. Dev.= 0.01 0.01 0.01
0.19
0.02 0.09
0.05 0.03 0.05 0.21
Approx. Min. Detectable Concn., P .P.M . 25 25 25
Dev., yo of Contained Amt. 4.5 4.2
3.0
--
...
0.2 11.1
I 3
5.8
100 100
8.2 1.8 1.2 6.1
300 500
1000
adsorbed on unnieshed Celite 545 \vas used. Column temperature n a s 90' C. and helium flow rate n-as 200 cc. per minute. Carbon Tetrachloride. T h e paraffinCelite column used for t h e analysis of 1,2-dichloroethane was used also for t h e analysis of carbon tetrachloride. A helium f l o ~rate of 125 cc. per minute and a temperature of 70" C. were used. Chloroform. T h e paraffin-Celite column was operated a t 65' C. and t h e helium floiv rate n'as 100 cc. per minute. 1-Chlorobutane. X Perkin-Elmer A column (didecyl phthalate on Celite 515) was operated a t 85' C., and a helium flow-rate of 100 cc. per minute -n-as used. RESULTS AND DISCUSSION
1,2-Dichloroethane.
This
VOL. 31, NO. 6, JUNE 1959
com1013
..t
C
D >/
I 48
46
44
I
42 '>18
16
14
12
10
I
1
8
6
Retention time, minutes
Figure 2.
Chromatogram of refined carbon tetrachloride
Column, paraffin on Celite
meters X 4.7 mm. Temperature 70a C. Recorder attenuation in parentheses C. Carbon tetrachloride (32) D. Chloroform (1 )
545, 2
Flow, 125 cc. of He per minute. A. Tetrachloroethylene ( 1 ) 8. Trichloroethylene ( 1 )
pound may be produced by the chlorination of ethylene. T h e by-products are mono-, di-, tri-, and tetrachlorosubstituted derivatives of ethane and ethylene. Analysis of a mixture containing the compounds normally present in unrefined 1,2-dichloroethane is given in Table I. The chromatographic method was cheaper than the mass spectrometric method yet equally precise, accurate, and rapid. A chromatogram of the unrefined lj2-dichloroethane is presented as Figure 1. All compounds normally present in this mixture are completely resolved. Chloroprene (2-chloro-1,3butadiene), if present, is not resolved quantitatively from cis-dichloroethylene; however, its concentration is normally insignificant-it.,
