DETERMINATION OF THE VAPOR PRESSURE OF DIETHYLTOLUENE DIAMINE (DETDA) 

WILDLIFE INTERNATIONAL, LTD. PROJECT NUMBER: 471C-146 

U.S. EPA Product Properties Test Guideline 

OPPTS 830.7950, Vapor Pressure 

and 

Organisation for Economic Cooperation and Development 

OECD Guideline 104: Vapour Pressure 

AUTHORS: 

William R. Schutt, B.S. 

Willard B. Nixon, Ph.D. 

STUDY INITIATION DATE: March 14, 2012 

STUDY COMPLETION DATE: June 27, 2012 

SUBMITTED TO: 

Albemarle Corporation 

451 Florida Street 

Baton Rouge, LA 70801 

Wildlife International, Ltd. 

8598 Commerce Drive 

Easton, Maryland 21601 

(410) 822-8600 

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TABLE OF CONTENTS 

Title/Cover Page ..................................................................................................................................... 1 

Good Laboratory Practice Compliance Statement ................................................................................. 2 

Quality Assurance Statement ................................................................................................................. 3 

Report Approval ..................................................................................................................................... 4 

Table of Contents ................................................................................................................................... 5 

Summary ................................................................................................................................................ 7 

Introduction ............................................................................................................................................ 8 

Objective ................................................................................................................................................ 8 

Experimental Design .............................................................................................................................. 8 

Materials and Methods ........................................................................................................................... 8 

 Test Substance ........................................................................................................................... 8 

 Reference Substance .................................................................................................................. 9 

 System Configuration ................................................................................................................ 9 

 Test Procedure ........................................................................................................................... 9 

 Calculations ............................................................................................................................. 10 

Results and Discussion ......................................................................................................................... 10 

Conclusions .......................................................................................................................................... 11 

References ............................................................................................................................................ 12 
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TABLE OF CONTENTS 

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TABLES

Table 1. Vapor Pressure Measurements and Out-Gassing Rates for Toluene 

 by the Static Method at 20 ± 1°C ...................................................................................... 13 

Table 2. Vapor Pressure Measurements and Out-Gassing Rates for DETDA 

 by the Static Method at 20 ± 1°C ...................................................................................... 14 

FIGURES

Figure 1. Diagram of high vacuum system configuration ................................................................ 15 

Figure 2. Image of the high vacuum system .................................................................................... 16 

Figure 3. Representative vapor pressure plot for toluene at 20 ± 1°C ............................................. 17 

Figure 4. Representative vapor pressure plot for DETDA at 20 ± 1°C ............................................ 18 

APPENDICES 

Appendix 1. Protocol ...................................................................................................................... 19 

Appendix 2. Characterization Report and Certificate of Analysis .................................................. 31 

 Test Substance .................................................................................................. 32 

 Reference Substance ......................................................................................... 35 

Appendix 3. Personnel Involved in the Study ................................................................................. 36 
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SUMMARY 

STUDY TITLE: Determination of the Vapor Pressure of Diethyltoluene Diamine 

(DETDA) 

WILDLIFE INTERNATIONAL, LTD. 

PROJECT NUMBER: 471C-146 

SPONSOR: Albemarle Corporation 

451 Florida Street 

Baton Rouge, LA 70801 

TESTING FACILITY: Wildlife International, Ltd. 

Easton, Maryland 21601 

SPONSOR’S REPRESENTATIVE: Marcia L. Hardy, DVM, Ph.D. 

LOCATION OF STUDY, RAW

DATA AND A COPY OF THE

FINAL REPORT: 

Wildlife International Ltd. 

Easton, Maryland 21601 

TEST SUBSTANCE: Diethyltoluene Diamine (DETDA) 

TEST DATES: Experimental OECD Start – March 26, 2012 

Experimental EPA Start – March 26, 2012 

Experimental Termination – April 1, 2012 

SUMMARY: The mean vapor pressure for DETDA at 20 ± 1°C was 32.4 ± 2.8 Pa 

(N = 3, CV = 8.7%) using the static method. 
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INTRODUCTION 

The vapor pressure of diethyltoluene diamine (DETDA) was determined at 20 ± 1°C using the 

static method. The study was conducted by Wildlife International, Ltd. for Albemarle Corporation at the 

Wildlife International, Ltd. chemistry facility in Easton, Maryland. Vapor pressure analyses were 

conducted from March 26, 2012 to April 1, 2012. Raw data generated by Wildlife International, Ltd. and 

a copy of the final report are filed under Project Number 471C-146 in archives located on the Wildlife 

International, Ltd. site. The original signed report will be maintained by Albemarle Corporation, Baton 

Rouge, Louisiana. 

OBJECTIVE 

The objective of this study was to determine the vapor pressure of DETDA at 20 ± 1°C. 

EXPERIMENTAL DESIGN 

The static method is applicable to both liquids and solids with vapor pressures at or above the 

upper range of the spinning rotor gauge method (0.5 Pa). Measurements were performed using a Pirani 

capacitance diaphragm manometer. The vacuum system and manometer were isolated from the test 

substance, maintained at a temperature of 20° ± 1°C, until ultimate vacuum was achieved. The system 

and manometer were then isolated from the vacuum pumps and the test material was introduced into the 

evacuated system. The pressure increase was monitored by the capacitance manometer at approximately 

one-second intervals. A linear regression was obtained for pressure increase as a function of time. The 

y-intercept of this regression corresponds to the vapor pressure of the sample. 

MATERIALS AND METHODS 

The study was conducted according to the procedures outlined in the protocol, “Determination of 

the Vapor Pressure of Diethyltoluene Diamine (DETDA)” (Appendix 1). The test was performed based 

on procedures in the U.S. EPA Product Properties Test Guidelines, OPPTS 830.7950, Vapor Pressure 

(1) and OECD Guideline for the Testing of Chemicals, 104: Vapour Pressure (2). 

Test Substance 

The test substance was received from Albemarle Corporation on September 21, 2011, and was 

assigned Wildlife International, Ltd. identification number 10232. The test substance was a liquid 

identified as DETDA; Lot number – 4500051816-011110. A purity of 97.27% was obtained from the 
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characterization report provided by the Sponsor (Appendix 2). The test substance was stored under 

ambient conditions. 

Reference Substance 

The toluene reference substance was received from Sigma-Aldrich Chemical Company on 

August 11, 2006, and was assigned Wildlife International, Ltd. identification number 7688 upon receipt. 

The reference standard, a liquid, was identified as: Toluene, anhydrous, 99.8%; lot number 01062LD; 

CAS number 108-88-3. The reference standard had a reported purity of 99.84%, and was stored in 

darkness under ambient conditions (Appendix 2). An expiration date of August 31, 2012 was assigned. 

System Configuration 

The high vacuum system consisted of a vacuum chamber configured with a mechanical vacuum 

pump (Edwards Model E2M2), a turbomolecular pump (Leybold TURBOVAC 50), a pirani capacitance 

diaphragm manometer (Inficon PCG400), all-metal isolation valves, a sample chamber and miscellaneous 

vacuum fittings required to assemble the components. The pirani gauge controller was connected to a 

computer via the serial interface (RS-232 port). A diagram of the apparatus configuration and an image 

of the high vacuum system are presented in Figures 1 and 2, respectively. 

The sample chamber consisted of a Pyrex tube (~2.5 cm o.d. X 12 cm) joined to a quick-fit type 

metal flange (NW-25). Empty sample chambers were used for background measurement. The 

temperature of the sample chamber was maintained at 20 ± 1°C during pressure measurements. A 

refrigerated recirculator, attached to a copper water jacket, regulated the temperature of the sample 

chamber. The minimum and maximum temperature of the sample chamber during measurement were 

recorded with a NIST-traceable digital thermometer. 

Test Procedure 

Prior to analysis of the reference or test substance, the vacuum system, including the capacitance 

manometer, was isolated from the sample chamber and evacuated to achieve ultimate vacuum. Once the 

system had achieved ultimate vacuum, the vacuum system was isolated from the vacuum pumps and the 

reference or test substance was introduced into the evacuated system. The rate of pressure increase due to 

out-gassing and permeation in the presence of the reference or test material was determined at least three 
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times at 20 ± 1°C. Pressure increase was measured for at least fifteen minutes after introduction of the 

reference or test material. 

A 5.00-mL aliquot of toluene was used as a vapor pressure reference to verify the accuracy of the 

system configuration. The vapor pressure of the reference substance by the static method was compared 

to the published values by the dynamic method (1). 

An approximate 5.00-gram aliquot of the test substance, DETDA, was used for vapor pressure 

determination. 

Calculations 

Least-squares-fit linear regression analysis was performed on the vapor pressure measurements 

collected after the valves to the vacuum pump were closed to determine the out-gassing rate. A minimum 

of ten data points from the end of the vapor pressure curve with an average rate of change for the 

replicates of less than or equal to 0.30% was used for the linear regression of the test substance since it 

provided the best linearity. In the absence of sample, the slope of the regression would be equal to the 

out-gassing rate of the system, and the y-intercept would be considered the baseline or background 

pressure. With sample present, the sample vapor pressure was also taken as the y-intercept of the 

corresponding regression line. 

RESULTS AND DISCUSSION 

The mean measured vapor pressure of the reference substance, toluene, by the static method was 

2976 ± 51 Pa at 20 ± 1°C. The vapor pressure was consistent with published values (2). Individual and 

mean measured vapor pressures (y-intercept of linear regression function) and the corresponding 

out-gassing rates (slope of linear regression function) for the reference substance at 20 ± 1C are 

presented in Table 1. A representative vapor pressure plot for toluene is presented in Figure 3. 

The mean measured vapor pressure of the test substance, DETDA, by the static method was 32.4 ± 

2.8 Pa at 20 ± 1°C. Individual and mean measured vapor pressures (y-intercept of linear regression 

function) and the corresponding out-gassing rates (slope of linear regression function) for the test 

substance at 20 ± 1C are presented in Table 2. A representative vapor pressure plot for DETDA is 

presented in Figure 4. 
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CONCLUSIONS 

The mean vapor pressure for DETDA at 20 ± 1°C was 32.4 ± 2.8 Pa (N = 3, CV = 8.7%) using the 

static method. 
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REFERENCES 

1. U.S. EPA Product Properties Test Guidelines. 1996. OPPTS 830.7950. Vapor Pressure.

2. Organisation for Economic Cooperation and Development. 2006. Guidelines for the Testing 

of Chemicals, 104: Vapour Pressure.
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Table 1 

Vapor Pressure Measurements and Out-Gassing Rates for Toluene 

by the Static Method at 20 ± 1C 

Measured 

Vapor Pressure 

(Pa) 

Min/Max 

Temperature 

(°C) 

Mean 

Measured 

Vapor Pressure1

(Pa) 

Standard 

Deviation 

(Pa) 

2975 

3027 19.6/20.0 2976 51 

2925 

1

Literature value was 3.0 x 103 Pa and range was 2.9 x 103 Pa to 3.1 x 103 Pa using the dynamic 

method (2). 

Measured 

Out-gassing Rate 

(Pa/s) 

Min/Max 

Temperature 

(°C) 

Mean 

Measured 

Out-gassing Rate 

(Pa/s) 

Standard 

Deviation 

(Pa/s) 

7.24 x 10-3 

-8.82 x 10-2 19.6/20.0 -2.28 x 10-2 5.67 x 10-2 

1.26 x 10-2 
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Table 2 

Vapor Pressure Measurements and Out-Gassing Rates for DETDA 

by the Static Method at 20 ± 1C 

Measured 

Vapor Pressure 

(Pa) 

Min/Max 

Temperature 

(°C) 

Mean 

Measured 

Vapor Pressure 

(Pa) 

Standard 

Deviation 

(Pa) 

29.1 

34.1 19.9/20.0 32.4 2.8 

33.9 

Measured 

Out-gassing Rate 

(Pa/s) 

Min/Max 

Temperature 

(°C) 

Mean 

Measured 

Out-gassing Rate 

(Pa/s) 

Standard 

Deviation 

(Pa/s) 

1.43 x 10-3 

1.67 x 10-3 19.9/20.0 1.57 x 10-3 1.27 x 10-4 

1.62 x 10-3 
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 1. Vacuum Pump 6. Turbomolecular Pump  2. Turbopump Controller 7. Capacitance Manometer  3. Capacitance Manometer Controller 8. Spinning Rotor Gauge (N 4. Spinning Rotor Gauge Controller (Not Used) 9. Sample Chambe 5. Computer Workstation Figure 1. Diagram of high vacuum system configuration. 
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Figure 2. Image of the high vacuum system. 
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-1.0E-04

5.0E+02

1.0E+03

1.5E+03

2.0E+03

2.5E+03

3.0E+03

3.5E+03

8:52:48 9:07:12 9:21:36 9:36:00 9:50:24

Time

Pascal

Figure 3. Representative vapor pressure plot for toluene at 20 ± 1°C. Arrow indicates time of valve 

closing (vacuum isolation) and introduction of sample into the evacuated system. 

9:10:08
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-1.0E-04

5.0E+00

1.0E+01

1.5E+01

2.0E+01

2.5E+01

3.0E+01

3.5E+01

7:55:12 8:09:36 8:24:00 8:38:24 8:52:48

Time

Pascal

Figure 4. Representative vapor pressure plot for DETDA at 20 ± 1°C. Arrow indicates time of valve 

closing (vacuum isolation) and introduction of sample into the evacuated system. 

8:10:07
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Appendix 1 

Protocol 
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Appendix 2 

Characterization Report and Certificate of Analysis 
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Test Substance 
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Reference Substance 
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Appendix 3 

Personnel Involved in the Study 

The following key Wildlife International, Ltd. personnel were involved in the conduct or 

management of this study: 

 1. Willard B. Nixon, Ph.D., Director of Chemistry 

2. Raymond L. Van Hoven, Ph.D., Senior Scientist 

3. William R. Schutt, B.S., Chemist