National Institute for Occupational Safety and Health

“ Prepare a calibration graph for each anion [peak height (mm or μS) vs. concentration (μg per sample) ] .
ST OR
MEASUREMENT:
12.
Set ion chromatograph to conditions given on page 7903-1, according to manufacturer’s instructions. 13.
Inject 50-μL sample aliquot. For manual operation, inject 2 to 3 mL of sample from filter/syringe to ensure complete rinse of sample loop. NOTE: All samples, eluents and water flowing through the IC must be filtered to avoid plugging system valves or columns. 14. ”

“ The replacement methods (7906, 7907, & 7908) allow for the collection of inhalable fractions of acid aerosols by means of a prefilter and can provide for lower limits of detection for acid gases and vapors due to higher sampling flow rates. ”

“ Pour sample into 10-mL plastic syringe fitted with in-line filter. CALIBRATION AND QUALITY CONTROL:
IC
AL
11.
Calibrate daily with at least six working standards covering the range 0.001 to 0.3 mg of each anion per sample. a. Add known aliquots of calibration stock solution to eluent in 50-mL volumetric flasks and dilute to the mark. b. Store working standards in tightly-capped polyethylene bottles. Prepare fresh working standards weekly. c. Analyze working standards together with samples and blanks (steps 12 through 14) . d. ”