P-Chlorobenzotrifluoride (1026)
p-CHLOROBENZOTRIFLUORIDE C7 H4 ClF3
MW: 180.56
METHOD: 1026, Issue 1
CAS: 98-56-6
RTECS: XS9145000
EVALUATION: PARTIAL
PROPERTIES:
OSHA : Not Established NIOSH: Not Established ACGIH: Not Established (1 ppm = 7.41 mg/m )
1026
Issue 1: 15 March 2003
liquid; d 1.353 g/mL @ 20 °C; BP 139°C; VP 5.3 mm Hg @ 20 °C
3
SYNONYMS:
4-Chlorobenzotrifluoride, 1-Chloro-4 (trifluoromethyl) benzene, 4-Chloro-",","-trifluorotoluene, PCBTF
SAMPLING SAMPLER:
Coconut Shell Charcoal (CSC) (100/50 mg)
FLOW RATE:
0.01 to 0.2 L/min
VOL-MIN: -MAX:
0.1 L 10.0 L (25 ppm)
SHIPMENT:
Routine
SAMPLE STABILITY:
7 days @ 25°C; 30 days @ 5 °C
BLANKS:
10% of field samples
MEASUREMENT TECHNIQUE:
GAS CHROMATOGRAPHY, FID
ANALYTE:
p-Chlorobenzotrifluoride
DESORPTION:
1 mL of carbon disulfide/methanol (99:1)
INJECTION VOLUME:
1 µL
TEMPERATURE-INJECTION: 250°C -DETECTOR: 300°C -COLUMN: 40°C (1 min) to 150°C (10°C/min) CARRIER GAS:
Helium; 2.8 mL/min
COLUMN:
capillary, fused silica, 30-m x 0.32 mm ID; 1 µm film 100% crossbonded dimethyl polysiloxane
CALIBRATION:
Solutions of p-CBTF in solvent
RANGE:
1.8 µg to 676 µg [1]
ACCURACY RANGE STUDIED:
Not Determined
BIAS:
Not Determined
OVERALL PRECISION (Ö r T ):
Not Determined
ACCURACY:
Not Determined
ESTIMATED LOD: 0.6 µg [1] PRECISION ( þ r ):
0.0131 [1]
APPLICABILITY: The working range for p-chlorobenzotrifluoride was 0.024 to 9.15 ppm (0.178 to 67.8 mg/m3 ) for a 10-L air sample. [1]
INTERFERENCES: Any compounds having similar retention times may co-elute with the analyte of interest.
OTHER METHODS:
None determined.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition p-CH LOR OB ENZ OT RIFLU OR IDE: ME TH OD 1026, Issue 1, dated 1 5 Ma rch 2003 - Page 2 of 3 REAGENTS: 1. 2. 3. 4. 5. 6. 7.
EQUIPMENT:
p-Chlorobenzotrifluoride, 98%. Carbon d isulfide, low benzene grade*. Me thanol, HPLC grade *. Helium, purified. Air, prefiltered and purified. Hydrogen, purified. Calibration stock: Dilute 5 µL of p-CBTF in 10 mL solvent. Prepare remaining standards by serial dilutions.
- See SPECIAL PRECAUTIONS
1. Sam pler: glass tube, 7 cm long, 6-mm ID, 4mm ID, flame-sealed ends, containing two sections of activated coconut shell charcoal (front = 100 mg, back = 50 mg) separated by a 2-mm urethane foam plug. A silylated glass wool plug precedes the front section and a 3mm urethane foam plug follows the back section. Tubes are comm ercially available. 2. Personal sampling pump, 0.01 to 0.2 L/min, with flexible tubing. 3. Gas chromatograph, FID, integrator, and Rtx1, or equivalent, fused silica capillary column. 4. Autosampler vials, glass, 1.8 mL, with PTFElined caps. 5. Syringes, 10-µL to 1-mL. 6. Volumetric flasks, 10-mL and 250-mL. 7. Pipets, various sizes.
SPECIAL PRECAUTIONS: Carbon disulfide is toxic and flamm able. Methanol is moderately toxic and flam m able. Perform all work in a ch em ical hood and w ear a ppro priate prote ctive equipm ent. p-CBTF is an irritant compound.
SAMPLING: 1. Calibrate each personal sampling pump with a representative sample tube in line. 2. Break ope n the end s of th e sa m ple tub e im m ediately prior to s am pling. Attach sam ple tub e to personal sampling pump with flexible tubing. 3. Sam ple at a n ac curately kn own flow ra te betwee n 0.01 an d 0.2 L/m in for a total sam ple size of 0.1 to 10 L. 4. Ca p bo th ends of the s am ple tub es a nd p ack sec urely for shipm ent.
SAMPLE PREPARATION: 5. Pla ce the initial glass wool plug and front so rbent se ctio n of the sam ple tube in an autos am pler vial. Place the back sorbent section of the sample tube in a separate autosampler vial. Discard the polyurethane foam separator and the remaining glass wool plug. 6. Add 1.0 m L of c arbo n disu lfide/m etha nol (99:1) s olven t to eac h vial an d ca p se curely. 7. Allow to stand fo r 30 m inutes with oc cas ional agitation.
CALIBRATION AND QUALITY CONTRO L: 8. Calibrate daily with at least six working calibration standards from below the LOD to 10 times the LO Q. If nece ssa ry additional standa rds m ay be a dde d to exten d the calibra tion cu rve. a. Add k nown a m ounts of calibration stock solution to carbon disulfide/methan ol (99:1) in 10-mL volumetric flasks and dilute to the mark. b. Analyze together with samp les and blanks (steps 10 and 11). c. Prepare calibration graph (peak area vs. µg p-CBT F). 9. Dete rm ine the desorption efficiency (DE) at least once for each batch of c harcoal used for sam pling in the calibration range (step 8). a. Prepare three tubes at each of five levels plus three media blanks.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition p-CH LOR OB ENZ OT RIFLU OR IDE: ME TH OD 1026, Issue 1, dated 1 5 Ma rch 2003 - Page 3 of 3 b. c. d. e.
Inject a known amount of analyte stock solution directly onto the front sorbent section of each charcoal tube. Allow the tub es to air equ ilibrate for several m inutes , then cap the ends of the tubes an d allow to stan d overnight. Deso rb (steps 5-7) and a nalyze together with standards and blanks (steps 10 and 11). Prepare a graph of DE vs. µg p-CB TF reco vere d.
MEASUREMENT: 10. Set gas chromatograph according to manufacturer’s recomm endations and to conditions given on page 1026-1. Inject a 1-µL sample aliquot manually using the solvent flush technique or with an autosam pler. NOTE: If peak area is above the linear range of the working standards, dilute with carbon disulfide/methanol (99:1), reanalyze and apply the appropriate dilution factor in the calculations. 11. Measure peak areas.
CALCULATIONS: 12. Determ ine the ma ss, µg (correc ted for DE), for p-chlorobenzotrifluoride found in the sam ple front (W f) and bac k (W b) sorbent sections, and in the averag e m edia blank front (B f) and back (B b) sorbent sec tions. NOTE: If W b > W f/10, report breakthrough and possible sample loss. 13. Calculate conce ntration, C, of p-chlorobenzotrifluoride in the air volume sam pled, V (L):
EVALUATION OF METHOD: This m ethod developm ent was ba sed upo n an health hazard evaluation request where p-chlorobenzotrifluoride was being us ed as a clean ing solvent for auto m obile parts. After an evaluatio n of va rious solid sorbent tubes and solvent/solvent m ixtu res, c oconut s hell charcoal tubes and carbon disulfide/m eth anol (99:1) solvent were selected for use in this method development. The desorption efficiency (DE) was determined for p-chlorobenzotrifluoride at 4 levels ranging from 27.1 µg to 541.2 µg. The average DE de termined for pchlorobenzotrifluoride was 100.6%. The LOD was determined to be 0.6 µg/sample. The analytical method precision, as determined from the pooled relative standard de viation (S r), was determined to be 0.01 31. Para-chlorobenzotrifluoride was determined to have acceptable storage stability (102.6%) for 30 days [1] at a level 0.1 times the recomm ended exposure level suggested by the manufacturer. [2]
REFERENCES: [1] Pende rgrass SM [2000]. Backu p Data for p-Ch lorobenzo trifluoride Me thod Develop m ent, NIOS H/CE MB , Cincinnati, OH ., (NIOSH , unpublished report July). [2] OC C [1998]. Ma terial safety data sheet for p-chlorobenzotrifluoride. Dallas, Texas: Occidental Chem ical Co rporatio n, M ay.
METHOD WRITTEN BY: Stephanie M. Pendergrass, NIOSH/ DART.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition