1-NITROPYRENE IN DIESEL PARTICULATES C16 H9 NO2
MW: 247.26
METHOD: 2560, Issue 1
CAS: 5522-43-0
RTECS: UR2480000
EVALUATION: PARTIAL
OSHA : no PEL NIOSH: no REL ACGIH: no TLV
PROPERTIES:
2560
Issue 1: 15 March 2003
solid; d 1.246 g/cc @ 20 °C; MP 154157 °C; BP 231 °C
SYNONYMS: None
SAMPLING
MEASUREMENT
SAMPLER:
FILTER (Glass Fiber, 37-mm)
TECHNIQUE:
GAS CHROMATOGRAPHY, NITROGEN CHEMILUMINESCENCE DETECTOR
FLOW RATE:
1.0 to 2.0 L/min
ANALYTE:
1-Nitropyrene
VOL-MIN: -MAX:
480 L 960 L
DESORPTION:
1 mL toluene; place on a rotary shaker for minimum of 12 hours.
SHIPMENT:
Ship in container at ambient temperature.
INJECTION VOLUME:
SAMPLE STABILITY:
At least 28 days @ 25 °C
BLANKS:
2 to 10 field blanks per set
ACCURACY RANGE STUDIED:
Generated atmospheres not studied
BIAS:
Not determined
TEMPERATURE -INJECTION: -DETECTOR: -COLUMN:
Not determined
250 °C Furnace: 850 °C Initial: 100 °C, ramp at 7.5 °C/min to 305 °C
CARRIER GAS:
Helium @ 10.0 mL/min (splitless)
COLUMN:
Capillary, fused silica, 30m x 0.53-mm ID; 1.5 µm film 5% diphenyl-95% dimethyl polysiloxane.
CALIBRATION:
Liquid standard solutions of 1-nitropyrene in toluene.
RANGE:
0.020 to 50 µg per sample
OVERALL PRECISION (Ö r T ): Not determined ACCURACY:
20 µL
ESTIMATED LOD: 0.010 µg per sample (see Evaluation of Method) PRECISION ( þ r ):
0.02 @ 1 to 50 µg per sample
APPLICABILITY: The working range is 0.021 to 104 µg/m3 for a 500 L sample. An appropriate range of calibration standards should be used to bracket the expected analyte concentration range. Because of sensitivity and accuracy considerations, a single calibration curve will not be appropriate for the entire working range. This method was developed to analyze 1nitropyrene in a diesel particulate matrix (see Figure 2). INTERFERENCES: None identified - however, compounds with a similar retention time may interfere. Positive identification may be confirmed by dual column chromatography using an appropriate alternative capillary column. Identification can also be confirmed by mass spectrometry. OTHER METHODS: None identified.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition 1-NITR OP YRE NE: M ETH OD 2560, Issue 1, dated 1 5 Ma rch 2003 - Page 2 of 5 REAGENTS:
EQUIPMENT:
1. To luene, HPLC or GC grade .* 2. NIST , SRM 1650, Diesel Particulate Matter. 3. 1-Nitropyrene Standard Solution, 5000 µg/mL in toluene. (A ccu Stan dard Inc., N ew H aven, CT , or equivalen t).* 4. 1-Nitropyrene Standard Solution, 1000 µg/mL in toluene. (A ccu Stan dard Inc., N ew H aven, CT , or equivalen t).*
1. Sam pler: Glass fiber filter (Type A/E) 1-:m pore size, 37-mm diameter (Gelman Sciences, A nn A rbor, MI, or equ ivalent), back ed by a cellulose support pad 37 -m m OD, in a two part, 37-mm cassette filter holder. 2. Spacer Ring, 37 mm (SKC, Eighty Four, PA or eq uivalen t). NOTE: For calibration and QC sam ples, filter space r rings are used instead of a sup port p ad. 3. Personal sampling pump capable of operatin g fo r 8 h r at 2 L/m in, w ith flexible connecting tube. 4. Lab qua ke Rotary Shaker or equ ivalent. 5. Vials, Autosampler, glass with PTFE-lined crimp top cap, 1.8 mL. 6. Micro volume inserts for autosampler vials. 7. Forceps. 8. Syringes, glass: 5-µL, 10-µL, 1-mL, other sizes as needed. 9. Syringe filter with tube tip, 4-mm , 0.45-µm, PVDF. 10. Syringe, disposable: 1-mL volume. 11. Gas Chrom atograph: HP-5890 with HP-7673 Au tos am pler (or eq uivalent), An tek Model 704E N itrogen Chem ilum inescence Detector (or equivalent). Restek Rtx-5-ms®, 30 m X 0.32 mm id., 1.0-:m film thickness (or equivalent).
- See SPECIAL PRECAUTIONS
SPECIAL PRECAUTIONS:1-Nitropyrene is a cancer suspect agent and mutagen. Toluene is a flamm able liquid, toxic. SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Sam ple at an accurately known flow rate of 1.0 to 2.0 L/min for a volume of 480 to 960 L. 3. After the sample is collected, place the plastic plugs in the tubing connector stubs on the sampling cassette.
SAMPLE PREPARATION: 4. Extract Filters: a. Rem ove the filter from the cass ette with a pair of forceps, discard the support pad, fold the filter and transfer to a G C autos am pler vial. b. Add 1 mL of toluene and cap the vial with a septum crimp top. c. Place the vial on the rotary shaker. Rotate the samples for a minimum of 12 hours. 5. Prepare the filter extract for analysis. a. Carefully remove the septum cap from the vial containing the extracted filter. b. Using a transfer pipette, remove a s m uch liquid extract from the extraction vial as possible and transfer to a 1 mL disposable syringe with a 4-mm syringe filter attached. c. Filter the extract into a micro volume insert in a GC autosampler vial. Cap the vial with a septum crim p ca p. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition 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 1-NITR OP YRE NE: M ETH OD 2560, Issue 1, dated 1 5 Ma rch 2003 - Page 4 of 5 The method LOD and LOQ as determined using spiked media samples were 3.4 ng/sample and 11.5 ng/sample respectively. However, because the detector was operating at its m ax im um sen sitivity settings, the normal baseline noise at th e lowe st analyte levels often m ade the peak d ifficult to be pro perly integrated. Therefore, more realistic and repeatable values for the LOD and LOQ are 10 and 20 ng/sa m ple respectively. Average recoveries of 1-nitropyrene from spiked glass fiber filters ranged from 88.4% to 101.2% for an alyte quantities of 1.0 to 50.0 :g/filter using liquid standards as the spiking solution. Recovery of 1-nitropyrene from NIST SRM-1650 Diesel Particulates weighed on glass fiber filters and carried through the extraction and sam ple preparation process yielded recoveries of 73% to 114% (see NOTE) for sample quantities of 1.63 mg to 26.6 mg. A thirty day storage stability study of 1-nitropyrene spiked on glass fiber filters indicates that the recovery of the analyte at a level of 10 :g/filter is 102%. The samples were stored in a closed cardboard container at room tem pera ture fo r the duration of th e study.
NOTE: The rated concentration of the NIST SRM -1650 for 1-Nitropyrene is 19+2 ug/g diesel particulate. The unc ertainty in the am ount is +10.5%. This accounts for the wide range of recoveries of the NIST standard, particularly at the low am ounts used in the recovery studies which were used to mim ic the real world samples.
REFERENCES: [1] [2] [3] [4]
IARC [1984]. 1-Nitropyrene. IARC M onograph on Evaluation of Cancer Risk of Chem icals to Humans, 33:209-22, Apr. IARC [1997]. 1-Nitropyrene. IARC M onograph on Evaluation of Cancer Risk of Chem icals to Humans, 46:321 -358 , Apr. NIST [1991]. “Certificate of Analysis.” Standard R eference Material 1650, Diesel Particulate Matter. Gaithersburg, MD: National Institute of Standards and Technology, Decem ber 12. Jaycox LB [2002]. Backup Data Report, 1-Nitropyrene. Cincinnati, OH: National Institute for Occupational Safety and He alth, DART . (unpublished report).
METHOD WRITTEN BY: Larry B. Jaycox, Ph.D., NIOSH/DART
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition 1-NITR OP YRE NE: M ETH OD 2560, Issue 1, dated 1 5 Ma rch 2003 - Page 5 of 5
FIGURE 1: Th is is a chromatogram of a 1-nitropyrene 60 ng standard . The m ajor p eak at approx imately 22.5 minutes is 1-nitropyrene. This chromatogram shows some hydrocarbon response and a baseline with a higher than normal noise level due to the effort to obtain as much sensitivity as possible for samples in the low nanogram region.
FIGURE 2: The chromatogram shown here is from the analysis of the NIST SRM -1650 Diesel Particulates. The diesel particulate, 2.10 mg, was weighed on a glass fiber filter and carried through the com plete s am ple extra ction a nd p repa ration proc edu re. The q uan tity of 1-nitrop yrene in this sa m ple was 3 9.9 µ g.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition