Page:NIOSH Manual of Analytical Methods - 2560.pdf/3

 1-NITR OP YRE NE: M ETH OD 2560, Issue 1, dated 1 5 Ma rch 2003 - Page 3 of 5 CALIBRATION AND QUALITY CONTRO L: 6. Ca librate daily with at least six calibration standards to cover the concentration range of the sam ples. A typical gas chromatogram is shown in Figure 1. a. Prepare calibration standards by adding known am ounts of the 1-nitropyrene standard solution or a secondary stock solution prepared from the standard solution to a GC autosampler vial containing 1 mL toluene. b. Analyze with samp les and blanks (steps 9 & 10 ). c. Prepare a calibration graph (pe ak area vs. µg 1-nitropyrene). 7. Determine the recovery (R) of the analyte from the sampling media using the glass fiber filters with analyte spikes in the concentration range of the sam ples (see step 6). Prepare three filters at each of five levels plus three media blanks. a. Place a filter spacer ring in the bottom section of a two part 37 mm filter cassette. Place a 37 mm glass fiber filter on top of the space r ring (do not use a supp ort pad). b. Inoc ulate the filter with a k now n am oun t of ca libration s tock solution with a m icroliter syringe, place the top section of the cassette in place and seal the filter in place by squeezing the two sections together. c. Place the plugs in the inlet and outlet tubing stubs and set the cassettes aside for a minimum of twelve hou rs. d. Prepare the filter samples (steps 4 & 5) and analyze with the calibration standards. e. Prepare a graph of R vs. µg 1-nitropyrene. 8. Analyze three quality control blind spik es and three analyst spikes to ensure that the calibration graph and R gra ph are in control.

MEASUREMENT: 9. Set gas chromatograph according to manufacturer’s recomm endations and to conditions given on page 2560-1. Inject sample with autosampler or by manual injection. NOTE: If peak are a is above the linear range of the calibra tion sta nda rds, dilute the sam ple with toluene, reanalyze, and apply the appropriate dilution factor in calculations. 10. Measure peak area of 1-nitropyrene peak and determine µg per sample from calibration graph.

CALCULATIONS: 11. Determ ine the ma ss, µg (correc ted for R) for the sam ple (W ), and average m edia blank (B). 12. Calculate conce ntration, C, of 1-nitropyrene in the air volum e sam pled, V(L):

NO TE : m g/L = m g/m 3

EVALUATION OF METHOD This m ethod was not evaluated with laboratory generated air samples. All of the recovery, storage studies, and LOD/LOQ determinations have been performed with laboratory spiked filters for the development of this method.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition