ETHYL ETHER MW: 74.14
(C2 H5 )2 O METHOD: 1610, Issue 3
1610
CAS: 60-29-7
RTECS: KI5775000
EVALUATION: FULL
Issue 1: 15 May 1985 Issue 3: 15 March 2003
PROPERTIES: liquid; d 0.7134 g/mL @ 20 o C; BP 34.6 o C; MP - 116 o C; VP 59 kPa (440 mm Hg; 58% v/v) @ 20 o C; explosive range 1.7 to 48% v/v in air
OSHA : 400 ppm NIOSH: no REL ACGIH: 400 ppm; STEL 500 ppm (1 ppm = 3.03 mg/m3 @ NTP)
SYNONYMS: diethyl ether; 1,1'-oxybisethane; ethyl oxide
SAMPLING SAMPLER:
Solid Sorbent Tube (coconut shell charcoal, 100 mg/50 mg)
MEASUREMENT TECHNIQUE:
GAS CHROMOTOGRAPHY, FID
ANALYTE:
ethyl ether
DESORPTION:
1.0 mL CS2 ; 30 min with agitation
INJECTION VOLUME:
1 µL
FLOW RATE: 0.01 to 0.2 L/min VOL-MIN: -MAX:
0.25 L @ 400 ppm 3L
SHIPMENT:
routine
SAMPLE STABILITY:
14 days @ 5 o C
BLANKS:
2 to 10 field blanks per set
ACCURACY RANGE STUDIED:
606 to 2400 mg/m3 (3-L samples)[2]
BIAS:
5.2%
OVERALL PRECISION (Ö r T ):
0.088
ACCURACY:
+ 20%
TEMPERATURE: -INJECTION: 250 o C -DETECTOR: 300 o C -COLUMN: 35 o C (1 min) - 150 o C @ 10 o C/minute, (split 5:1) CARRIER GAS:
helium (1-2 mL/min)
COLUMN:
capillary, fused silica 30 m x 0.32-mm ID; 1-:m film 100% dimethyl polysiloxane, Rtx-1 or equivalent
CALIBRATION:
solutions of ethyl ether in CS 2
RANGE:
2 to 430 µg per sample (capillary column); 1800 to 7100 µg per sample (packed column)
ESTIMATED LOD: 0.2 µg per sample PRECISION ( þ r ):
0.071 @ 9 to 400 µg per sample
APPLICABILITY: The working range is 100 to 2700 mg/m3 (33 to 880 ppm) for a 3-L air sample. During sampling, high humidity may greatly decrease the breakthrough volume. A sampling period of 15 min may be monitored for STEL compliance using a flow rate of 0.2 L/min.[3]
INTERFERENCES: Any compound, such as pentane, with similar retention times.
OTHER METHODS: This revises Method S80 [4] and NMAM 1610 (issue 2) [4].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ETH YL ET HER : MET HO D 161 0, Issue 3, dated 15 M arch 200 3 - Page 2 o f 4 REAGENTS:
EQUIPMENT:
1. 2. 3. 4. 5.
1.
Ca rbon Disu lfide, low ben zene grad e.* Ethyl ether, rea gen t grad e.* Helium, prepurified and filtered. Hydrogen, prepurified and filtered. Air, prepurified and filtered.
- See SPECIAL PRECAUTIONS.
2. 3. 4. 5. 6. 7.
Sam pler: glass tube, 7 cm long, 6-mm OD, 4mm ID, flame-sealed ends with plastic caps, containing two sections of activated (600 oC) 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 3-mm urethane foam plug follows the back section. Pressure drop across the tube must be less than 3.4 kPa at 1 L/m in airflow. T ubes are com m ercially available. Personal sampling pump, 0.01 to 0.2 L/min, with flexible connecting tubing. Gas chromatograph, FID, integrator and colum n (see pag e 1610-1). Vials, glass, 2-mL, PTFE -lined caps. Syringe, 10-µL, 25-µL, 250-µL. Flasks, volumetric 10-mL. Pipet, volumetric, 1-mL with pipet bulb.
SPECIAL PRECAUTIONS: Ethyl ether is a dangerous fire and explosion hazard (flash point = -45 oC) and tends to form explosive peroxides. Carbon disulfide is toxic and flamm able (flash point = -30 oC). Prepare samples and standards in a well-ventilated hood.
SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Break the ends of the sampler imm ediately before sampling. Attach sampler 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 0.25 to 3 L. 4. Ca p the sam plers. Pac k secu rely for shipm ent.
SAMPLE PREPARATION: 5. Place the front and back sorbent sections of the sampler tube in separate vials. Include the glass wool plug in the vial with the front sorbent section. 6. Ad d 1.0 m L carbon disulfide to each vial. Attac h cap to each vial. 7. Allow to stand 30 min with occasional agitation.
CALIBRATION AND QUALITY CONTRO L: 8. Ca librate daily with at leas t six wo rking standa rds from below the LOD to 10 times the LO Q. If nec ess ary, additional stand ards m ay be a dde d to exten d the calibra tion cu rve. a. Add known amounts of ethyl ether to carbon disulfide in 10-mL volumetric flasks and dilute to the mark. Prepare additional standards as needed by serial dilution. b. Analyze together with samp les and blanks (steps 11 and 12). c. Prepare c alibration graph (pe ak area vs. µg ethyl ether per sam ple).
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ETH YL ET HER : MET HO D 161 0, Issue 3, dated 15 M arch 200 3 - Page 3 o f 4 9. Determine desorption efficiency (DE) at least once for each lot of charcoal used for sampling in the calibra tion ran ge (s tep 8). a. Prepare three tubes at each of five levels plus three media blanks. b. Rem ove and disca rd the back sorbent sec tion of a blank sam pler. c. Inject a known amount (1 to 20 µL) of ethyl ether or a standard solution of ethyl ether in carbon disulfide directly onto the front sorbent section with a microliter syringe. d. Ca p the tube. Allow to stand overnight. e. Deso rb (steps 5 through 7 ) and analyze together with working standards (steps 11 and 12). f. Prepare a graph of DE vs. µg ethyl ether recovered. 10. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and D E graph are in control.
MEASUREMENT: 11. Set gas chromatograph according to manufacturer's recomm endations and to conditions given on pag e 16 10-1 . Inject s am ple aliqu ot m anu ally using solve nt flush technique o r with autos am pler. NOTE: If peak area is above the linear range of the working standards, dilute an aliquot of the desorbed sam ple with carbon disulfide, reanalyze , and apply the appropriate dilution fa cto r in the calculations. 12. Measure peak area.
CALCULATIONS: 13. Determ ine the ma ss, µg (correc ted for DE), of ethyl ether found in the sam ple front (W f) and back (W b) sorbent sections, and in the averag e m edia blank front (B f) and back (B b) sorben t sec tions. NOTE: If W b > W f/10, report breakthrough and possible sample loss. 14. Calculate conce ntration, C, of ethyl ether in the air volume sa m pled, V (L):
EVALUATION OF METHOD: Issues 1 and 2 Method S80 was issued on February 14, 1975 [4], and evaluated over the rang e 63 0 to 2500 m g/m 3 at 22 °C and 766 mm Hg for 3-L air samples desorbed in 0.5 mL ethyl acetate [2]. The concentrations were verified by using a total hydrocarbon ana lyzer. Breakthrough (5% on the backup section) occurred at 33 min when sampling a concentration of 247 0 m g/m 3 in dry air at a flow rate of 0.185 L/min., corresponding to a capa city of 15 m g. The average DE was 98% over the range 1.8 to 7.1 mg ethyl ether per sample. Sample storage stability was not determined. Issue 3 The sensitivity of this m etho d for ethyl ethe r was lowered to cover a range from approximately 10 times the LOQ (based upon an improved LOD of 0.2 µg/sample) to 500 times (0.25 REL) the LOQ. The desorption efficiency was tested at four levels over the range of 8 - 428 :g/sample. The average recovery for ethyl ether over this ran ge w as 1 02.5 %. A 30-day storage stability study for ethyl ether was completed during the method developm ent. Th e storage stab ility was d etermined at a level approximately 0.2 REL. The analyte was dete rm ined to be stable for 14 da ys when s tored at 5°C with an average reco very of 90.3% [1].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ETH YL ET HER : MET HO D 161 0, Issue 3, dated 15 M arch 200 3 - Page 4 o f 4 REFERENCES: [1] Pendergrass SM , Ma y LR [2000 ]. NM AM 161 0, Issue 3 , Bac kup Data R epo rt. Cincinnati, OH: National Institute for O ccu pation al Safety & H ealth, D AR T (u npu blishe d), Ap ril. [2] NIO SH [197 7]. Docum entation of the NIOSH Validation Tests, S80, U.S. Department of Health, Education, and W elfare, Publ. (NIOSH) 77-185, available as GPO Stock #017-033-00231-2 from Superintendent of Documents, W ashington, DC 20402. [3] NIOSH/OSHA [1981]. NIO SH /OS HA Oc cup ationa l Hea lth Gu idelines for C hem ical Hazard s, U.S. Department of Health and Hum an Services and U.S. Department of Labor, January 1981, Publ. (NIOSH) 81-123, available as GPO Stock #17-033-00337-8 from Superintendent of Documents, W ashington, D.C. 20402. [4] NIOSH [1977]. NIO SH Ma nua l of Analytical Methods, 2nd e d., Vol. 2, S80, U.S. Department of Health, Education, and W elfare , Pub l. (NIO SH ) 77-157 -B. S80 originally validated under NIOSH Contract CDC-99-74-45.
AUTHORS: Stephanie Pendergrass, NIOSH/DART. Leroy R. May, NIOSH/ PRL. Method originally written by Robert W . Kurimo, NIOSH/DART.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition