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SUPER ABSORBENT POLYMERS: METHOD 5035, Issue 1, dated 15 August 1994 - Page 5 of 6 pooled Sr was 0.086). A second method for calculation of precision involved division of the standard error of the calibration curve by the average y value (average value of copper); precision for the analytical method ( Sr) = 16.7/247 = 0.068. This sampling and analytical method (Method 5035, Cu-SAP method) was compared with the sodium method [2] for determination of Sanwet IM-3500 in area air samples at a diaper manufacturing plant. Comparison of Cu-SAP Method (Filters Only) with Sodium Method Set

Analytical Method

Volume of Air (liters)

Average Concentration of Sanwet IM-3500 (mg/m 3)

Relative Standard Deviation

1a 1b

Cu-SAP sodium

840 908

0.0673 0.108

0.19 0.023

2a 2b

Cu-SAP sodium

425 420

0.0978 0.162

0.35 0.052

Air samples for each method were collected at 2 liters/min. Sets 1a and 1b had three samples each; sets 2a and 2b had two samples each. Although PVC filters and interior surfaces of front pieces of cassette filter holders were analyzed in the Cu-SAP method, interior surfaces were not analyzed in the sodium method; thus, the comparisons above are for PVC filters only. Quantities of Sanwet IM-3500 found on interior surfaces of front pieces of cassettes ranged from 12 to 39% of the total quantities found. A bulk sample of Sanwet IM-3500 from the diaper plant contained 7.20% water. See additional information in reference [2]. The average of six blanks was 2.95 µg of copper, and the standard deviation of these blanks was 1.04 µg of copper (cellulose ester filters will retain small quantities of copper during filtration of copper acetate solutions and rinses with deionized water). Average recoveries of 8-, 17-, 63-, and 526-µg quantities of Sanwet IM-3500 from 37-mm PVC filters were 1.27, 0.84, 0.83 and 1.01, respectively. A standard mixture of Sanwet IM-3500 in sucrose (4.48% Sanwet IM-3500 by weight) was stable during storage in a vial for a period of more than eight months at room temperature. Digestion procedures involving (a) nitric and perchloric acids and (b) nitric acid only were evaluated for digestion of copperpolymer precipitate prepared from 500-µg quantities of Sanwet IM-3500. The two procedures were found to be equally effective.

REFERENCES: [1] [2]

Masuda, F., "Super Absorbent Polymers--Characteristics and Trends in Development of Applications," Chemical Economy & Engineering Review, 15(11):19-22 (1983). Tucker, S.P., M.B. Millson, and D.D. Dollberg, "Determination of Polyacrylate Super Absorbent Polymers in Air," Analytical Letters, 26(5):965-980 (1993).

METHOD WRITTEN BY: Samuel P. Tucker, Ph.D., Mark B. Millson, and Donald D. Dollberg, Ph.D., NIOSH/DPSE

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