GLUTARALDEHYDE: METHOD 2531, Issue 2, dated 15 August 1993 - Page 4 of 5 EVALUATION OF METHOD: Atmospheres were generated by injection of an aqueous solution of glutaraldehyde by syringe pump into a heated block injector and flash vaporization into a stream of air flowing at a fixed rate [1]. Relative humidity during generation was controlled at 80% ±5%. The generator and sampling manifold systems have been described previously [4]. Concentration of glutaraldehyde vapor was independently verified by the 2,4-dinitrophenylhydrazine procedure of Lipari and Swarin [5]. No bias with dynamicallygenerated atmospheres was observed with the method over the range 0.8 to 8 mg/m 3 using 22-L air samples. Desorption efficiencies on statically-spiked samples averaged 87% in the ranges 5 to 50 µg/sample. Recovery averaged 1.10 with s r = 0.043 for twelve tubes spiked with 67 µg glutaraldehyde [6].
REFERENCES: [1]
[2] [3] [4] [5]
[6]
Kennedy, E.R., Y.T. Gagnon, J.R. Okenfuss, and A.W. Teass. "The Determination in Air of Selected Low-Molecular Weight Aldehydes as Their Oxazolidines by Capillary Gas Chromatography," Appl. Ind. Hyg., 3:274-279 (1988). NIOSH Sequence Reports 5827 (Nov. 13, 1987) and 6565-J (Feb. 27, 1989) (unpublished). The Merck Index, 10th ed., Merck & Co., Rahway, NJ (1983). Kennedy, E.R. and R.H. Hill, Jr. "Determination of Formaldehyde in Air as an Oxazolidine Derivative by Capillary Gas Chromatography," Anal. Chem., 54:1739-1741 (1982). Lipari, F. and S.J. Swarin. "Determination of Formaldehyde and other Aldehydes in Automobile Exhaust with an Improved 2,4-Dinitrophenylhydrazine Method," J. Chromatog. , 247:297-306 (1982). DataChem Inc., UserCheck, NIOSH Seq. #6565-M (Unpublished, June 12, 1989).
METHOD WRITTEN BY: Julie R. Okenfuss and Eugene R. Kennedy, Ph.D., NIOSH/DPSE.
APPENDIX: A. PREPARATION AND STANDARDIZATION OF GLUTARALDEHYDE STOCK SOLUTION (ca. 10 µg/µL): Dilute 1 mL 25% aqueous glutaraldehyde to 25 mL with distilled, deionized water. Put 10.0 mL 1.13 M sodium sulfite solution in a beaker and stir magnetically. Adjust pH to between 8.5 and 10 with base or acid. Record the pH. Add 1.0 mL glutaraldehyde stock solution. The pH should be about 12. Titrate the solution back to its original pH with 0.02 N sulfuric acid. If the endpoint pH is overrun, back-titrate to the endpoint with 0.01 N sodium hydroxide. Calculate the concentration, C (µg/µL), to the glutaraldehyde stock solution:
where: 50.06 = equivalent weight of glutaraldehyde N a = normality of sulfuric acid V a = volume of sulfuric acid (mL) used for titration N b = normality of NaOH V b = volume of NaOH (mL) used for titration V s = volume of glutaraldehyde stock solution (1.0 mL).
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/93
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