ESTERS 1 Formulas: Table 1
MW: Table 1
METHOD: 1450, Issue 3
CAS: Table 1
RTECS: Table 1
EVALUATION: FULL
PROPERTIES:
OSHA : Table 1 NIOSH: Table 1 ACGIH: Table 1
COMPOUNDS:
1450
n-amyl acetate 2-ethoxyethyl acetate n-propyl acetate
1-butyl acetate methyl isoamyl acetate sec-butyl acetate
Issue 1: 15 February 1984 Issue 3: 15 March 2003
Table 1
isobutyl acetate n-butyl acetate isoamyl acetate
ethyl acrylate
SYNONYMS: See Table 1
SAMPLING SAMPLER:
SOLID SORBENT TUBE (coconut shell charcoal, 100 mg/50 mg)
MEASUREMENT TECHNIQUE:
GAS CHROMATOGRAPHY, FID
ANALYTE:
Compounds referenced above
DESORPTION:
1 mL CS2 , 30 min
INJECTION VOLUME:
1 µL
FLOW RATE: 0.01 to 0.2 L/min VOL-MIN: -MAX:
1 L @ OSHA PEL 10 L
SHIPMENT:
Refrigerated
SAMPLE STABILITY:
See EVALUATION OF METHOD
BLANKS:
2 to 10 field blanks per set
TEMPERATURE -INJECTION: -DETECTOR: -COLUMN:
200 - 225 °C 250 - 300 °C 50 °C for 2 minutes, then up to 110 °C at a rate of 5 °C per minute, holding at 110 °C for 3 minutes.
ACCURACY
CARRIER GAS:
4 mL/min, Helium
RANGE STUDIED:
0.5 to 2x OSHA PEL[1]
COLUMN:
ACCURACY:
See EVALUATION OF METHOD
Capillary, fused silica, 30m x 0.32mm ID; 0.5 µm film DB-Wax or equivalent.
BIAS:
See EVALUATION OF METHOD
CALIBRATION:
Solutions of compounds in CS2
RANGE:
See EVALUATION OF METHOD and Table 1.
LOD:
See EVALUATION OF METHOD
PRECISION ( Ö r ):
See EVALUATION OF METHOD [1]
OVERALL PRECISION ( Ö r T ):
See EVALUATION OF METHOD
APPLICABILITY: This method can be used for simultaneous analysis of all analytes. High humidity greatly reduces sampler capacity and breakthrough volume.
INTERFERENCES: None identified.
OTHER METHODS: This method, NMAM 1450, Issue 3 is an updated analytical procedure [5]. This method originally combined and replaced the NMAM 2nd edition Methods S31, S32, S35, S37, S41, S44 through S48, and S51 [3]. Estimated LOD for each analyte is approximately 10 times lower than that of the previous methods.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition EST ERS 1: MET HO D 145 0, Issue 3, dated 15 M arch 200 3 - Page 2 o f 6 REAGENTS:
EQUIPMENT:
1.
1. S am pler: glass tube, 7-cm long, 6-mm OD, 4m m ID, flame-sealed ends, containing two sections of activated (600 °C) coconut s hell charcoal (front - 100 mg; back - 50 mg) separated by a 2-m m ureth ane foam plug. A silylated glass wool plug precedes the front section and a 3-m m urethane foam plug follows the back section. Pressure drop across the tube at 1 L/m in airflow must be less than 3.4 kPa. Tubes are comm ercially available. 2. Personal sampling pump, 0.01 to 0.2 L /m in, with flexible connecting tubing. 3. Refrigerant, bagged (“Blue Ice,” or equivalent). 4. Gas chromatograph, FID, integrator and column (page 145 0-1). 5. Vials, glass, 2-mL, PTFE -lined crimp caps. 6. Syringe, 10-µL, readable to 0.1 µL, 25-, 50- and 100-µL. 7. Volumetric flasks, 10-mL. 8. Pip et, volumetric, 1-mL, with pipet bulb or repipet.
2. 3. 4. 5.
Desorbing solution: Carbon disulfide* (chromatographic grade) with 0.05% (v/v) nhexane or other suitable internal standard. Analyte, reagent grade. Helium, purified. Hydrogen, prepurified. Air, compressed, filtered.
- See SPECIAL PRECAUTIONS
SPE CIAL PR ECAU TIO NS: Carbon disulfide is toxic and an acute fire and explosion hazard (flash point = -30 °C); work with it only in a hood. W ear appropriate protective clothing and gloves.
SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler tube in line. 2. Break the ends of the sampler tube immediately before sampling. Attach sampler tube to personal sampling pump with flexible tubing. 3. Sa m ple at an accurately known flow rate between 0.01 and 0.2 L/min for a total sam ple size of 1 to 10 L. 4. Cap the sam plers with plastic (not rubber) caps and pack securely for shipm ent w ith bag ged refrige rant.
SAMPLE PREPARATION: 5. Place the front and back sorbent sections of the sampler tube in separate vials. Discard the glass wool and foam plugs. 6. Ad d 1.0 m L desorbing solution to each vial. Attac h crim p cap to each vial. 7. Allow to stand 30 min with occasional agitation. NOTE: The desorption efficiency of 2-ethoxyethyl acetate has been found to decrease with the resident tim e of the des orbe d so lution with charcoal [4]. After 30 min desorption transfer the supernatant solution of 2-ethoxyethyl acetate to a clean 2-mL vial and seal with a crimp cap.
CALIBRATION AND QUALITY CONTRO L: 8. Calibrate daily with at least six working standards over the range 0.001 to 10 mg analyte per sample. a. Add k now n am ounts of analyte to desorbing solution in 10-mL volumetric flasks and dilute to the m ark . b. Analyze together with samp les and blanks (steps 11 and 12). c. Prepare calibration graph (ratio of peak area of ana lyte to pea k area o f internal stan dard vs.m g analyte).
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition EST ERS 1: MET HO D 145 0, Issue 3, dated 15 M arch 200 3 - Page 3 o f 6 9. Determine desorption efficiency (DE) at least once for each lot of charcoal used for sampling in the calibration range (step 8). Prepare three tubes at each of five concentrations plus three media blanks. a. Rem ove and disca rd back sorbent sec tion of a blank sam pler. b. Inject a known amount of analyte directly onto front sorbent section with a microliter syringe. c. Ca p the tube. Allow to stand overnight. d. Deso rb (steps 5 through 7 ) and analyze together with working standards (steps 11 and 12). e. Prepare a graph of DE vs. mg analyte recovered. 10. Analyze three quality control blind spikes and three ana lyst spikes to insure that the calibration graph and DE graph are in control.
MEASUREMENT: 11. Set gas chrom ato graph acc ording to m anufacturer’s recomm endations and to conditions given on page 145 0-1. Inject sam ple aliqu ot with a utos am pler, or m anu ally using solve nt flush technique. NOTE: If peak area is above the linear range of the working standards, dilute with desorbing solution, reanalyze, and apply the appropriate dilution factor in calculations. 12. Mea sure pea k area. Divide the peak area of analyte by the peak area of internal standard on the same chromatogram.
CALCULATIONS: 13. De termine the m ass , (:g, corrected for DE ) of analyte found in the samp le front (W f) and back (W b) sorbent sec tions and in the average m edia blank front (B f) and back (B b) sorben t sec tions. NO TE: If W b > W f/10, report breakthrough and possible sample loss. 14. Calculate conce ntration, C, of analyte in the air volume sam pled, V (L):
EVALUATION OF METHOD: Previous Evaluation The original methods for S31 (sec-amylacetate), S47 (n-butyl acetate), S46 (sec-butyla cetate ), S32 (t-b utyl acetate), S41 (2 -etho xy acetate ), S35 (ethyl acrylate), S45 (iso am yl aceta te), S4 4 (is obutyl ace tate), S 37 (m eth yl isoamyl acetate), S48 (n-propyl acetate) were issued on December 6, 1974, ex cept for S51 (n -am yl acetate), which was issued on January 17, 1975 [3]. Atmospheres of each compound were generated in dry air by calibrated syringe drive and 10-L air samples were taken [1]. Collection efficiency in humid air and sample storage stability were not tested. Spiked samplers were used to study measurement precision and des orption efficienc y (DE). Current Evaluation Methods for esters (n-amyl acetate, n-butyl acetate, sec-butyl acetate, t-butyl acetate , 2-eth oxyeth yl acetate, eth yl acrylate, isoamyl acetate, isobutyl aceta te, m eth yl isoam yl acetate, n-propyl acetate) were evaluated [5] using analytes fortified on Anasorb CSC sorbent tubes (Lot #2000). Desorption efficiency (DE) and precision are shown in Table 2. Sec -am yl aceta te was evaluated in the previous issue of this method but it was not includ ed in th is current update. Storage stability studies were performed on Anasorb C SC tubes (Lo t #2000) at approxim ate ly 150 µg each analyte/sample. The s am ples were stored for up to 30 days at 4 °C. T he recove ries of 30-day storage are summ arized in Table 2. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition EST ERS 1: MET HO D 145 0, Issue 3, dated 15 M arch 200 3 - Page 4 o f 6 REFERENCES: [1] NIOSH [1977]. Docum entation of the NIOSH Validation Tests. U.S. Department of Health, Education and W elfare, Publ. (NIOSH) 77-185. [2] UTBL [1983]. UTBL user check, NIOSH Sequence #4121-N (unpublished), November 15. [3] NIO SH [1977]. NIO SH Ma nua l of Analytical Metho ds, 2 nd ed., V.2., U.S. Department of Health, Education and Welfare, Publ. (NIOSH) 77-157-B. [4] Corelson D [1988]. Menlo Park, CA., SRI. Personal communication with NIOSH. [5] Yoon YH, Perkins JB, Reynolds JM [2002]. Back-up Data Report for Esters 1, DataChem Laboratories, Inc. under NIOSH contracts CDC-200-95-2955 and CDC 200-2001-08000.
PRE VIOU S RE VISION BY : Robert W . Kurimo, NIOSH/DPSE ; methods originally validated under NIOSH C ontract CDC 99-74-45. METHOD REVISED BY: Young H ee Yoon, Ph .D., Ja m es B. P erkin s and John M. Reynolds, D ata Chem Laboratories, Inc ., Salt Lake City, Utah.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition EST ERS 1: MET HO D 145 0, Issue 3, dated 15 M arch 200 3 - Page 5 o f 6 Table 1. General Information Compound, Formula and RTECS
a b
Synonyms
M.W.
OSHA/NIOSH/ACGIH, ppm
BP, °C
VP @ 20 °C, kPa (mm Hg)
Liquid Density, g/mL @ 20 °C
n-amyl acetate CH3 COO(CH2 )4 CH3 ; C7 H1 4 O2 AJ1925000
acetic acid 1-pentanol ester; CAS #628-63-7
130.18
TWA (STEL) 100/100/100
149
0.5(4)
0.876
sec-amyl acetate CH3 COOCHCH3 (CH2 )2 CH3 ; C7 H1 4 O2 AJ2100000
acetic acid 2-pentanol ester; CAS #626-38-0
130.18
125/125/125
134
0.9(7)
0.866
n-butyl acetate CH3 COO(CH2 )3 CH3 ; C6 H1 2 O2 AF7350000
acetic acid butyl ester; CAS #123-86-4
116.16
150/150(200)/150(200)
126
1.3(10)
0.883
sec-butyl acetate CH3 COOCH(CH3 )CH2 CH3 ; C6 H1 2 O2 AF7380000
acetic acid 1-methyl propyl ester; CAS #105-46-4
116.16
200/200/200
112
1.3(10)
0.865
t-butyl acetate CH3 COOC(CH3 )3 ; C6 H1 2 O2 AF7400000
acetic acid 1, 1-dimethylethyl ester; CAS #540-88-5
116.16
200/200/200
98
not available
0.867
2-ethoxyethyl acetate CH3 COO(CH2 )2 OCH2 CH3 ; C6 H1 2 O3 KK8225000
Cellosolve acetate; acetic acid ethylene glycol monoethyl ether ester; CAS #111-15-9
132.16
100a /0.5a /5a
156
0.3(2)
0.973
ethyl acrylate CH2 =CHCOOCH2 CH3 ; C5 H8 O2 AT0700000
2-propenoic acid ethyl ester; CAS #140-88-5
100.11
25a /4 LOQb /5a b (15 ppm)
99
3.9(30)
0.923
isoamyl acetate CH3 COO(CH2 )2 CH(CH3 )2 ; C7 H1 4 O2 NS9800000
acetic acid 3-methyl-1-butanol ester; CAS #123-92-2
130.18
100/100/100
142
0.5(4)
0.876
isobutyl acetate CH3 COOCH2 CH(CH3 )2 ; C6 H1 2 O2 AI4025000
acetic acid isobutyl ester; CAS #110-19-0
116.16
150/150/150
117
1.7(13)
0.871
methyl isoamyl acetate CH3 COOCH(CH3 )CH2 CH(CH3 )2 ; C8 H1 6 O2 SA7525000
acetic acid 4-methyl-2-pentanol ester; 1,3-dimethyl butyl acetate; “sec-hexyl acetate;” CAS #10884-9
144.22
50/50/50
146
0.5(3.8)
0.858
n-propyl acetate CH2 COO(CH2 )2 CH3 ; C5 H1 0 O2 AJ3675000
acetic acid n-propyl ester; CAS #109-60-4
102.13
200/200 (250)/200 (250)
102
3.3(25)
0.890
Skin Carcinogen
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition EST ERS 1: MET HO D 145 0, Issue 3, dated 15 M arch 200 3 - Page 6 o f 6 Table 2. Current Method Evaluation Overall Method
Storage Stability Study
Range (mg/m3 )
Accuracy
Breakthrough1 at 2 x OSHA PEL (# )
Bias (%)
S RT
Range Studied (µg/sample)
LOD (µg/sample)
Average DE
Measurement Precision (Ö r )
Levels (µg/sample)
Recovery (%)
n-amyl acetate
208-871
0.163
34.2 L
0.3
0.0831
14-440
0.9
0.96
0.0072
140
98
n-butyl acetate
352-1475
0.136
20.5 L
0.3
0.0691
15-440
0.9
0.96
0.0087
140
98
sec-butyl acetate
478-2005
0.116
16.5 L
-2.4
0.0539
14-440
0.9
0.97
0.0062
140
98
t-butyl acetate
424-1780
0.234
14.3 L
-8.6
0.0897
14-430
0.9
0.98
0.0052
140
98
2-ethoxyethyl acetate
262-1100
0.203
34.6 L
-9.6
0.0648
16-340
1
0.82
0.020
160
96
ethyl acrylate
50-210
0.162
>45 L
-7.1
0.0550
31-300
2
0.86
0.015
150
90
isoamyl acetate
208-874
0.195
32.3 L
-7.1
0.0750
14-430
0.9
0.97
0.0066
140
98
isobutyl acetate
306-1280
0.133
21.5 L
1.8
0.0656
14-440
0.9
0.97
0.0084
140
98
methyl isoamyl acetate
143-601
0.126
>45 L
-2.6
0.0590
14-280
0.9
0.81
0.015
140
95
n-propyl acetate
384-1610
0.162
17.9 L
6.9
0.0566
15-450
0.9
0.95
0.0091
140
98
Compound
1
Analytical Method
The values for these categories were taken from the original methods validation, see ref [1].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition