Page:NIOSH Manual of Analytical Methods - 5030.pdf/4

 CYANURIC ACID: METHOD 5030, Issue 2, dated 15 August 1994 - Page 4 of 4 CALCULATIONS: 15. 16. 17.

Determine the mass, µg (corrected for R), of cyanuric acid found on the filter (W f) and on the average media blank (B f). Determine the mass, µg, of cyanuric acid found on the interior surface of the cassette filter holder (W c) and on the interior surface of a blank cassette filter holder (B c). Calculate concentration, C, of cyanuric acid in the air volume sampled, V (L):

EVALUATION OF METHOD: Average recoveries after fortification of 37-mm PVC membrane filters with 12-, 36-, and 412-µg quantities of cyanuric acid were 0.98, 1.00, and 1.00, respectively; precision ( Sr) was 0.020 (16 samples, pooled). The average recovery of 36-µg quantities of cyanuric acid from PVC filters after 22 days of storage at room temperature was 1.08; Sr was 0.065 (5 samples). Recovery of 1.08 was not significantly different from 1.00 at the 95% confidence level. Recoveries of 10-, 80-, 200-, and 400-µg quantities of cyanuric acid were 0.88, 1.04, 0.98 and 0.98, respectively, after storage of fortified PVC filters for 69 days at room temperature (one sample at each level). This method was not evaluated with controlled atmospheres in a laboratory. However, the method was employed for measurement of cyanuric acid in air at a plant in which trichloroisocyanuric acid was manufactured from cyanuric acid [1,5]. Significant quantities (ca. 40% of the totals) of cyanuric acid were found on interior surfaces of the front pieces of cassette filter holders. Working standards of cyanuric acid at concentrations near 1 µg/mL in eluent deteriorated in about 3 weeks during storage at room temperature; standards were stable for at least 18 days during storage at - 3 °C. Deterioration of a C 18 analytical column took place and caused the LOD of cyanuric acid to increase from 0.1 to 0.25 µg/mL during 6 weeks. Trichloroisocyanuric acid is an interference because it reacts with water (present in the eluent) to form cyanuric acid. Average yields of cyanuric acid after treatment of 8.4-, 64-, and 424-µg quantities of trichloroisocyanuric acid with eluent in glass vials were 74%, 89%, and 93%, respectively.

REFERENCES: [1] Tucker, S.P., and L.M. Blade. Anal. Lett. 25 (12), 2265-2277 (1992). [2] Briggle, T. V., L. M. Allen, R. C. Duncan, and C. D. Pfaffenberger. J. Assoc. Off. Anal. Chem., 64 (5), 1222-1226 (1981). [3] Canelli, E. Amer. J. Pub. Health. 64 (2), 155-162 (1974). [4] Hammond, B. G., S. J. Barbee, T. Inoue, N. Ishida, G. J. Levinskas, M. W. Stevens, A. G. Wheeler and T. Cascieri. Environ. Health Perspect ., 69, 287-292 (1986). [5] Tucker, S. Analytical Report for DPSE/MRSB Analytical Sequence #6426, NIOSH, Unpubl. (1989).

METHOD WRITTEN BY: Samuel P. Tucker, Ph.D., NIOSH/DPSE.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94