Volatile Organics Quality Assurance
The field equipment for canister sampling must be:
- easy to diagnosis problems
- start and stop on time accurately
- have a steady and controllable flow rate
- must establish a complete seal under vacuum and pressure to insure sample integrity
- sample must not be contaminated by the pump and other internal parts of the sampler
The QA program for the sampler is designed to check all the factors listed above. Every sample (new or repaired) undergoes testing for:
- accuracy of timer and flow controller under two different flow rates.
- cleanliness of infernal parts in the sample flow path (target compounds must be below 0.2 ppbv after zero air blank test in the lab)
- leak test for 30 minutes
- ease of operation
Field operations are designed to insure proper sampler operation and sample integrity.
- The operator leak tests the sampler every time a new sampling event is set up. If a leak test is failed, measures are taken to repair the system untll the leak test is passed (or sampler is replaced).
- If a canister has less than 25 inches of Hg vacuum, it is not used as it has leaked since it was sent to the field.
- If the final pressure is less than 5 psig it is noted on the field form and central office staff will prepare another sampler in case the next sample is also below 5 psig. Nominal pressure from the field should be 10 psig.
- If a sample arrives in the lab at ambient pressure it is not analyzed because it has leaked and sample integrity has been compromised. The field operator is notified to make certain a good seal is formed on removal of the canister form the sampler.
- Any sample problems are noted on the field form and logged into the database to track problems with the canisters and samplers.
LABORATORY ANALYSIS
Laboratory functions must be tested routinely to insure high quality data. Accuracy and precision are checked quarterly and annually to track system performance. Calibration standards are analyzed before, during and after every batch of samples. Instrument tuning is checked prior to every analytical run.
In addition:
- A re-analysis of a sample is performed at a rate of once every 10 sample analysis.
- Every sample is leak tested prior to beginning an analytical run.
- The cryogenic sample concentrator tracks flow rates and temperatures for every sample and creates a report of that sample for analyst review.
Quality Assurance Report for the Bureau of Air Quality Surveillance
Toxics Sampling Network
Sampling Precision Analysis
prepared by:
Bureau of Quality Assurance
Quality Assurance Section
The following tabulations and graphical presentation were developed based on analysis of duplicate samples at New York State's toxics air monitoring sites.
Each sampling site has three sample channels that operate simultaneously every six days. One sample channel is a low flow channel that operates at approximately 7 cc/min. The other two channels are high flow and operate at approximately 15 cc/min. The two high flow samples from each site are analyzed independently and the mean and standard deviation of the percent difference between the two samples calculated for each sample pair. From this, the 95% confidence limits are calculated for each compound using the equation:
mean +/- [1.96 x (Std. Dev)]
Although the mean of the percent differences between the sample pairs for most compounds are small, the standard deviations are in most cases large. This is because small differences in very low concentrations, i.e. 1.0 ppb compared to 0.5 ppb, result in large percent differences. The results are broad 95% confidence limits. This information is valuable, however, since it illustrates the variability that can be expected between individual sample pairs.
This information is useful to those evaluating ambient toxics sampling data, since it illustrates the degree of uncertainty associated with each sample result.
| Compound | No. Sample Pairs | Mean % | Std. Dev. % | Lower Limit | Upper Limit |
|---|---|---|---|---|---|
| Dichloromethane | 50 | 1.6 | 12.4 | -23 | 26 |
| Chloroform | 10 | 9.2 | 8.9 | -8 | 27 |
| 1,2 Dichloroethane | 1* | ||||
| 1,1,1 Trichloroethane | 76 | 3.4 | 21.0 | -38 | 45 |
| Benzene | 65 | 1.9 | 27.2 | -51 | 55 |
| Carbon Tetrachloride | 20 | 1.1 | 6.8 | -12 | 14 |
| Trichloroethylene | 34 | -0.8 | 19.7 | -39 | 38 |
| 1,1,2 Trichloroethane | 0* | ||||
| Toluene | 71 | 2.5 | 14.7 | -26 | 31 |
| Tetrachloroethylene | 37 | 4.7 | 23.3 | -41 | 50 |
| Chlorobenzene | 3* | ||||
| Ethylbenzene | 62 | 2.8 | 14.6 | -26 | 32 |
| M,P-Xylene | 73 | 3.7 | 16.3 | -28 | 36 |
| 0-Xylene | 64 | 1.0 | 13.9 | -26 | 28 |
| 1,3 Dichlorobenzene | 23 | -4.5 | 24.9 | -53 | 44 |
| 1,4 Dichlorobenzene | 0* | ||||
| 1,2 Dichlorobenzene | 0* |
*Insufficient data pairs to evaluate statistically
New York State
Department of Environmental Conservation
Division of Air Resources
Toxics Sampling Network
| Compound | No. Sample Pairs | Mean % | Std. Dev. % | Lower Limit | Upper Limit |
|---|---|---|---|---|---|
| Dichloromethane | 59 | 4.3 | 14.4 | -24 | 32 |
| Chloroform | 14 | 8.6 | 16.7 | -24 | 41 |
| 1,2 Dichloroethane | 0* | ||||
| 1,1,1 Trichloroethane | 93 | 0.7 | 16.3 | -31 | 33 |
| Benzene | 75 | 3.3 | 19.3 | -34 | 41 |
| Carbon Tetrachloride | 4 | 1.8 | 7.6 | -13 | 17 |
| Trichloroethylene | 27 | 3.1 | 17.5 | -31 | 37 |
| 1,1,2 Trichloroethane | 0* | ||||
| Toluene | 88 | 1.8 | 19.3 | -36 | 40 |
| Tetrachloroethylene | 46 | 1.4 | 16.3 | -31 | 33 |
| Chlorobenzene | 1* | ||||
| Ethylbenzene | 83 | 0.8 | 17.3 | -33 | 35 |
| M,P-Xylene | 93 | 0.0 | 17.9 | -35 | 35 |
| 0-Xylene | 81 | 1.2 | 17.3 | -33 | 35 |
| 1,3 Dichlorobenzene | 39 | -1.5 | 12.4 | -26 | 23 |
| 1,4 Dichlorobenzene | 0* | ||||
| 1,2 Dichlorobenzene | 0* |
*Insufficient data pairs to evaluate statistically
New York State
Department of Environmental Conservation
Division of Air Resources
Toxics Sampling Network
| Compound | No. Sample Pairs | Mean % | Std. Dev. % | Lower Limit | Upper Limit |
|---|---|---|---|---|---|
| Dichloromethane | 59 | 5.1 | 21.5 | -37 | 47 |
| Chloroform | 19 | 4.3 | 29.4 | -53 | 62 |
| 1,2 Dichloroethane | 1* | ||||
| 1,1,1 Trichloroethane | 93 | -2.7 | 21.6 | -45 | 40 |
| Benzene | 72 | 3.4 | 20.9 | -38 | 44 |
| Carbon Tetrachloride | 9 | 7.2 | 22.7 | -37 | 52 |
| Trichloroethylene | 25 | 12.1 | 21.5 | -30 | 54 |
| 1,1,2 Trichloroethane | 0* | ||||
| Toluene | 95 | 2.3 | 16.6 | -30 | 35 |
| Tetrachloroethylene | 44 | 5.9 | 17.2 | -28 | 40 |
| Chlorobenzene | 3* | ||||
| Ethylbenzene | 88 | 2.7 | 15.4 | -28 | 33 |
| M,P-Xylene | 104 | 0.8 | 14.4 | -27 | 29 |
| 0-Xylene | 90 | 2.4 | 15.0 | -27 | 32 |
| 1,3 Dichlorobenzene | 43 | -0.8 | 22.1 | -42 | 44 |
| 1,4 Dichlorobenzene | 0* | ||||
| 1,2 Dichlorobenzene | 3* |
*Insufficient data pairs to evaluate statistically
New York State
Department of Environmental Conservation
Division of Air Resources
Toxics Sampling Network
| Compound | No. Sample Pairs | Mean % | Std. Dev. % | Lower Limit | Upper Limit |
|---|---|---|---|---|---|
| Dichloromethane | 64 | -1.0 | 31.3 | -62 | 60 |
| Chloroform | 24 | -0.9 | 21.3 | -43 | 41 |
| 1,2 Dichloroethane | 0* | ||||
| 1,1,1 Trichloroethane | 118 | -7.1 | 19.8 | -46 | 32 |
| Benzene | 112 | 4.3 | 23.2 | -41 | 50 |
| Carbon Tetrachloride | 43 | -5.6 | 18.4 | -42 | 30 |
| Trichloroethylene | 38 | 5.5 | 16.3 | -26 | 38 |
| 1,1,2 Trichloroethane | 0* | ||||
| Toluene | 112 | -0.1 | 16.7 | -33 | 33 |
| Tetrachloroethylene | 39 | 10.7 | 23.6 | -36 | 57 |
| Chlorobenzene | 11 | 6.6 | 11.8 | -16 | 30 |
| Ethylbenzene | 111 | 2.3 | 13.2 | -24 | 28 |
| M,P-Xylene | 118 | 2.1 | 13.8 | -25 | 29 |
| 0-Xylene | 112 | 1.3 | 12.0 | -22 | 25 |
| 1,3 Dichlorobenzene | 67 | 2.1 | 18.1 | -33 | 38 |
| 1,4 Dichlorobenzene | 0* | ||||
| 1,2 Dichlorobenzene | 2* |
*Insufficient data pairs to evaluate statistically
| Chemical | No. Sample Pairs | Avg. % Diff. | Standard Deviation | Lower Limit % | Upper Limit % |
|---|---|---|---|---|---|
| Benzene | 232 | 1.80 | 25.5 | 51.80 | -48.10 |
| Carbon Tetrachloride | 46 | -4.00 | 26.5 | 48.00 | -56.00 |
| Chlorobenzene | 8 | -13.90 | 18.9 | 23.20 | -51.00 |
| Chloroform | 6 | 0.80 | 5.6 | 11.80 | -10.20 |
| Methylene Chloride | 38 | 4.90 | 25.3 | 54.50 | -44.60 |
| Ethylbenzene | 212 | 2.70 | 26.8 | 55.20 | -49.70 |
| 1,3-dichlorobenzene | 16 | 10.10 | 28.0 | 65.10 | -49.90 |
| M,P-Xylene | 239 | 3.10 | 28.8 | 59.60 | -53.30 |
| 1,2-dichlorobenzene | all results less than minimum to calculate precision | ||||
| O-Xylene | 277 | 1.70 | 28.2 | 57.00 | -53.70 |
| 1,4-dichlorobenzene | 12 | 7.80 | 31.0 | 68.60 | -53.00 |
| Tetrachloroethylene | 107 | 3.20 | 35.3 | 72.30 | -65.90 |
| Trichloroethylene | 59 | 0.30 | 15.1 | 29.90 | -29.30 |
| Toluene | 355 | 0.00 | 32.3 | 63.50 | -63.40 |
| 1,1,1-trichloroethane | 169 | 3.10 | 27.2 | 56.50 | -50.20 |
| 1,1,2-trichloroethane | 2 | 33.90 | N/A | N/A | N/A |
| 1,2-dichloroethane | 44 | 11.00 | 37.2 | 83.90 | -61.80 |
| Chemical | No. Sample Pairs | Avg. % Diff. | Standard Deviation | Lower Limit % | Upper Limit % |
|---|---|---|---|---|---|
| Benzene | 525 | 0.20 | 27.5 | 54.00 | -53.70 |
| Carbon Tetrachloride | 11 | -11.20 | 30.9 | 49.30 | -71.70 |
| Chlorobenzene | 50 | -1.10 | 45.1 | 87.30 | -89.60 |
| Chloroform | 7 | -11.10 | 16.8 | 21.90 | -44.10 |
| Methylene Chloride | 55 | 1.70 | 25.6 | 52.00 | -48.50 |
| Ethylbenzene | 419 | -0.70 | 22.7 | 43.80 | -45.30 |
| 1,3-dichlorobenzene | 27 | -1.00 | 23.9 | 45.90 | 47.90 |
| M,P-Xylene | 414 | 0.40 | 20.6 | 40.80 | -40.00 |
| 1,2-dichlorobenzene | 8 | 5.80 | 0.1 | 6.00 | -5.50 |
| O-Xylene | 492 | -0.50 | 23.2 | 44.80 | -45.90 |
| 1,4-dichlorobenzene | 12 | 1.40 | 18.3 | 37.20 | -34.40 |
| Tetrachloroethylene | 151 | 2.40 | 32.5 | 66.20 | -61.30 |
| Trichloroethylene | 85 | 2.50 | 21.4 | 44.50 | -39.50 |
| Toluene | 761 | 1.10 | 31.2 | 62.30 | -60.30 |
| 1,1,1-trichloroethane | 70 | 0.40 | 31.4 | 61.90 | -61.10 |
| 1,1,2-trichloroethane | all results less than minimum to calculate precision. | ||||
| 1,2-dichloroethane | 18 | 3.20 | 39.9 | 81.40 | -74.90 |
| Chemical | No. Sample Pairs | Avg. % Diff. | Standard Deviation | Lower Limit % | Upper Limit % |
|---|---|---|---|---|---|
| Benzene | 404 | -4.20 | 22.4 | 39.60 | -48.00 |
| Carbon Tetrachloride | 3 | -3.30 | 0.5 | 2.40 | -4.30 |
| Chlorobenzene | 2 | -4.10 | NA | NA | NA |
| Chloroform | 2 | -15.50 | NA | NA | NA |
| Methylene Chloride | 27 | 9.20 | 31.9 | 71.70 | -53.30 |
| Ethylbenzene | 277 | -2.60 | 22.2 | 40.90 | -46.10 |
| 1,3 Dichlorobenzene | 6 | 3.00 | 31.4 | 64.60 | -58.70 |
| M,P-Xylene | 248 | -4.10 | 21.3 | 37.60 | -45.90 |
| 1,2 Dichlorobenzene | all results less than minimum to calculate pecision | ||||
| O-Xylene | 342 | -4.30 | 25.0 | 44.70 | -53.30 |
| 1,4 Dichlorobenzene | 34 | -7.50 | 18.2 | 28.20 | -43.30 |
| Tetrachloroethylene | 117 | -3.00 | 21.7 | 39.60 | -45.50 |
| Trichloroethylene | 72 | -0.50 | 9.7 | 18.50 | -19.40 |
| Toluene | 585 | -2.90 | 28.4 | 52.70 | -58.60 |
| 1,1,1 Trichloroethane | 26 | -1.50 | 36.9 | 70.80 | -73.80 |
| 1,1,2 Trichloroethane | all results less than minimum to calculate pecision | ||||
| 1,2 Dichloroethane | all results less than minimum to calculate pecision | ||||
| Chemical | No. Sample Pairs | Avg. % Diff. | Standard Deviation | Lower Limit % | Upper Limit % |
|---|---|---|---|---|---|
| Benzene | 270 | -0.30 | 26.7 | 52.10 | -52.70 |
| Carbon Tetrachloride | all results less than minimum to calculate pecision | ||||
| Chlorobenzene | all results less than minimum to calculate pecision | ||||
| Chloroform | all results less than minimum to calculate pecision | ||||
| Methylene Chloride | 28 | -3.60 | 31.9 | 72.00 | -79.50 |
| Ethylbenzene | 145 | -2.20 | 22.2 | 51.60 | -55.90 |
| 1,3 Dichlorobenzene | 1 | 5.60 | NA | NA | NA |
| M,P-Xylene | 181 | -2.10 | 29.6 | 55.90 | -60.00 |
| 1,2 Dichlorobenzene | all results less than minimum to calculate pecision | ||||
| O-Xylene | 241 | -4.20 | 29.3 | 53.20 | -61.50 |
| 1,4 Dichlorobenzene | 43 | 4.20 | 17.9 | 39.30 | -30.90 |
| Tetrachloroethylene | 53 | -1.80 | 23.5 | 44.20 | -47.80 |
| Trichloroethylene | 81 | 1.80 | 22.3 | 45.60 | -41.90 |
| Toluene | 480 | -5.10 | 31.90 | 57.50 | -67.70 |
| 1,1,1 Trichloroethane | 7 | 12.10 | 35.3 | 81.30 | -57.00 |
| 1,1,2 Trichloroethane | 1 | -81.50 | NA | NA | NA |
| 1,2 Dichloroethane | all results less than minimum to calculate pecision | ||||
| Chemical | No. Sample Pairs | Avg. % Diff. | Standard Deviation | Lower Limit % | Upper Limit % |
|---|---|---|---|---|---|
| Benzene | 160 | 1.30 | 23.8 | 47.90 | -45.30 |
| Carbon Tetrachloride | all results less than minimum to calculate pecision | ||||
| Chlorobenzene | all results less than minimum to calculate pecision | ||||
| Chloroform | all results less than minimum to calculate pecision | ||||
| Methylene Chloride | 27 | -0.30 | 27.6 | 53.70 | -54.40 |
| Ethylbenzene | 126 | -1.60 | 23.3 | 44.10 | -47.20 |
| 1,3 Dichlorobenzene | all results less than minimum to calculate pecision | ||||
| M,P-Xylene | 146 | -1.80 | 23.6 | 44.50 | -48.10 |
| 1,2 Dichlorobenzene | all results less than minimum to calculate pecision | ||||
| O-Xylene | 175 | -1.60 | 25.5 | 48.30 | -51.50 |
| 1,4 Dichlorobenzene | 34 | 3.10 | 28.1 | 58.10 | -51.90 |
| Tetrachloroethylene | 56 | -6.10 | 21.2 | 35.60 | -47.70 |
| Trichloroethylene | 25 | -2.20 | 19.2 | 35.40 | -39.80 |
| Toluene | 300 | -0.80 | 29.0 | 56.10 | -57.60 |
| 1,1,1 Trichloroethane | 1 | 65.60 | NA | NA | NA |
| 1,1,2 Trichloroethane | all results less than minimum to calculate pecision | ||||
| 1,2 Dichloroethane | all results less than minimum to calculate pecision | ||||
| Compound | Avg. % Diff. | Standard Deviation | Average Blank | MDL PPBv | Avg. Value |
|---|---|---|---|---|---|
| dichlorodifluoromethane | 2.70% | 13.30% | 0.07 | 0.10 | 0.76 |
| chloromethane | -0.44% | 21.64% | 0.04 | 0.10 | 0.51 |
| dichloroterafluoroethane | 1.22% * | 18.98% * | 0.04 | 0.10 | 0.03 |
| vinylchloride | -10.15% * | 90.15% * | 0.03 | 0.08 | 0.01 |
| bromomethane | -4.44% * | 15.52% * | 0.04 | 0.03 | 0.03 |
| chloroethane | 20.77% * | 72.76% * | 0.04 | 0.10 | 0.03 |
| trichloromonofluoromethane | -1.12% | 3.03% | 0.05 | 0.10 | 0.30 |
| 1,1-dichloroethene | -6.31% * | 13.80% * | 0.04 | 0.10 | 0.01 |
| dichloromethane | -7.43% | 29.82% | 0.11 | 0.25 | 0.24 |
| trichlorotrifluoroetha | 9.67% * | 47.74% * | 0.05 | 0.10 | 0.23 |
| 1,1-dichloroethane | 11.60% | 89.10% | 0.03 | 0.10 | 0.01 |
| cis 1,2-dichloroethene | -17.73% | 88.65% | 0.04 | 0.10 | 0.01 |
| chloroform | 1.40% | 4.97% | 0.09 | 0.02 | 0.08 |
| 1,2-dichloroethane | 2.66% | 75.34% | 0.05 | 0.01 | 0.02 |
| 1,1,1-trichloroethane | -0.97% | 3.78% | 0.07 | 0.03 | 2.50 |
| benzene | 0.83% | 12.84% | 0.12 | 0.04 | 0.57 |
| carbontetrachloride | -1.18% | 2.49% | 0.04 | 0.02 | 0.12 |
| 1,2-dichloropropane | 11.22% * | 50.60% * | 0.04 | 0.10 | 0.00 |
| trichloroethene | -6.11% * | 11.50% * | 0.06 | 0.02 | 0.07 |
| cis 1,3-dichloropropene | -7.64% * | 104.48% * | 0.04 | 0.10 | 0.01 |
| trans 1,3-dichloropropene | -10.10% * | 105.41% * | 0.04 | 0.10 | 0.01 |
| 1,1,2-trichloroethane | 2.04% * | 59.47% * | 0.03 | 0.03 | 0.01 |
| toluene | -14.98% | 49.92% | 0.20 | 0.04 | 1.20 |
| 1,2-dibromoethane | -10.12% * | 24.92% * | 0.05 | 0.10 | 0.01 |
| tetrachloroethene | -2.88% | 10.92% | 0.12 | 0.04 | 0.25 |
| chlorobenzene | 1.13% | 18.84% | 0.05 | 0.02 | 0.03 |
| ethylbenzene | -2.40% | 7.90% | 0.10 | 0.02 | 0.21 |
| m/p-xylene | 0.06% | 9.25% | 0.22 | 0.04 | 0.63 |
| styrene | -15.64% * | 23.07% * | 0.11 | 0.49 | 0.09 |
| 1,1,2,2-tetrachloroethane | 15.00% * | 50.33% * | 0.04 | 0.20 | 0.00 |
| o-xylene | -2.82% | 10.68% | 0.10 | 0.03 | 0.24 |
| 1,3,5-trimethylbenzene | -5.38% * | 23.12% * | 0.09 | 0.26 | 0.12 |
| 1,2,4-trimethylbenzene | -6.87% | 11.05% | 0.15 | 0.03 | 0.32 |
| Achlorotoluene | -38.13% * | 114.64% * | 0.04 | 0.10 | 0.06 |
| 1,3-dichlorobenzene | 6.75% * | 56.97% * | 0.08 | 0.03 | 0.03 |
| 1,4-dichlorobenzene | -1.64% | 7.99% | 0.08 | 0.04 | 0.10 |
| 1,2-dichlorobenzene | -5.33% * | 7.96% * | 0.08 | 0.03 | 0.02 |
| 1,2,4-trichlorobenzene | -34.18% * | 65.90% * | 0.13 | 0.16 | 0.03 |
| hexachlorobutadiene | -18.38% * | 49.64% * | 0.07 | 0.10 | 0.02 |
* Values at or below the MDL for the compound.
| Compound | MDL PPBv | Avg. Primary Samples | Avg. % Diff. | Standard Deviation | Average Blank PPBv | Max Blank PPBv |
|---|---|---|---|---|---|---|
| 1,3,5-trimethylbenzene | 0.26 | 0.069 | -5.38% | 33.46% | 0.0096 | 0.058 |
| 1,3-dichlorobenzene | 0.03 | 0.048 | -13.06% | 87.31% | 0.0088 | 0.043 |
| 1,4-dichlorobenzene | 0.04 | 0.064 | -8.22% | 47.26% | 0.0035 | 0.014 |
| 13Butadiene | 0.050 | 0.022 | -53.99% | 90.79% | 0.0000 | 0 |
| 2-chloroprene | 0.100 | 0.000 | 0.00% | 0.00% | 0.0000 | 0 |
| Achlorotoluene | 0.10 | 0.020 | -24.89% | 101.11% | 0.0026 | 0.015 |
| benzene | 0.04 | 1.148 | 10.50% | 28.39% | 0.0684 | 0.334 |
| Bromodichloromethane | 0.100 | 0.000 | 0.00% | 0.00% | 0.0009 | 0.008 |
| bromomethane | 0.03 | 0.007 | 27.51% | 74.87% | 0.0027 | 0.02 |
| carbontetrachloride | 0.02 | 0.139 | 2.84% | 25.13% | 0.0014 | 0.005 |
| chlorobenzene | 0.02 | 0.017 | 1.82% | 35.27% | 0.0061 | 0.027 |
| chloroethane | 0.10 | 0.000 | 0.00% | 0.00% | 0.0000 | 0 |
| chloroform | 0.02 | 0.044 | -18.15% | 45.56% | 0.0036 | 0.03 |
| chloromethane | 0.10 | 0.603 | 3.04% | 28.06% | 0.0041 | 0.022 |
| cis 1,2-dichloroethene | 0.10 | 0.001 | 2.54% | 54.04% | 0.0015 | 0.005 |
| cis 1,3-dichloropropene | 0.10 | 0.002 | 17.31% | 79.46% | 0.0028 | 0.015 |
| dichlorodifluoromethane | 0.10 | 0.913 | 1.14% | 25.84% | 0.0044 | 0.024 |
| dichloromethane | 0.25 | 0.143 | 30.61% | 72.11% | 0.1205 | 1.851 |
| dichloroterafluoroethane | 0.10 | 0.014 | 33.60% | 69.04% | 0.0009 | 0.007 |
| ethylbenzene | 0.02 | 0.136 | 29.35% | 56.37% | 0.0099 | 0.062 |
| hexachlorobutadiene | 0.10 | 0.041 | -20.29% | 144.34% | 0.0317 | 0.144 |
| m/p-xylene | 0.04 | 0.444 | 5.93% | 31.61% | 0.0307 | 0.175 |
| MTBE | 0.10 | 0.470 | -1.87% | 95.10% | 0.0021 | 0.014 |
| o-xylene | 0.03 | 0.216 | 6.97% | 60.04% | 0.0132 | 0.077 |
| styrene | 0.49 | 0.085 | 7.81% | 104.69% | 0.0273 | 0.157 |
| tetrachloroethene | 0.04 | 0.097 | 3.29% | 42.48% | 0.0047 | 0.015 |
| toluene | 0.04 | 1.076 | -2.37% | 14.03% | 0.0434 | 0.215 |
| trans 1,3-dichloropropene | 0.10 | 0.003 | 15.85% | 87.35% | 0.0015 | 0.016 |
| Tribromomethane | 0.050 | 0.003 | 21.00% | 43.95% | 0.1310 | 1.523 |
| trichloroethene | 0.02 | 0.028 | -2.85% | 70.04% | 0.0028 | 0.017 |
| trichloromonofluoromethane | 0.10 | 0.386 | 8.45% | 27.41% | 0.0027 | 0.013 |
| trichlorotrifluoroetha | 0.10 | 0.124 | -9.40% | 48.16% | 0.0017 | 0.009 |
| vinylchloride | 0.08 | 0.004 | -24.07% | 66.48% | 0.0068 | 0.101 |
| Compound | MDL PPBv | Avg. Primary Samples | Avg. % Diff. | Standard Deviation | Average Blank PPBv | Max Blank PPBv |
|---|---|---|---|---|---|---|
| dichlorodifluoromethane | 0.1 | 0.82 | -1.3 | 4.7 | 0 | 0.03 |
| chloromethane | 0.1 | 0.69 | 2.2 | 8.5 | 0 | 0.07 |
| dichlorotetrafluoroethane | 0.1 | 0.02 | 20.6 | 71.9 | 0 | 0.02 |
| vinyl chloride | 0.08 | 0.01 | 26 | 66.2 | 0 | 0.03 |
| 13-Butadiene | 0.05 | 0.08 | -25.8 | 72.8 | 0 | 0.05 |
| bromomethane | 0.03 | 0.02 | 10.9 | 118 | 0 | 0.03 |
| chloroethane | 0.1 | 0 | 0 | 0 | 0 | 0 |
| trichloromonofluoromethane | 0.1 | 0.42 | -0.8 | 3.8 | 0 | 0.03 |
| 11dichloroethene | 0.1 | 0.01 | 3.7 | 27.4 | 0 | 0.07 |
| dichloromethane | 0.25 | 0.46 | -6.3 | 44.2 | 0.01 | 0.13 |
| trichlorotrifluoroethane | 0.1 | 0.14 | 2 | 15.9 | 0 | 0.07 |
| 11dichloroethane | 0.1 | 0.01 | 0.1 | 58.4 | 0 | 0.03 |
| MTBE | 0.1 | 2.35 | -16.7 | 78.3 | 0.01 | 0.05 |
| 2-chloroprene | 0.1 | 0 | 10.8 | 45.8 | 0 | 0 |
| 12dichloroethene | 0.1 | 0.01 | -15.1 | 75.1 | 0 | 0.05 |
| chloroform | 0.02 | 0.05 | 7.2 | 43.1 | 0.01 | 0.04 |
| 12dichloroethane | 0.01 | 0.02 | 23.1 | 102.7 | 0.01 | 0.07 |
| 111trichloroethane | 0.03 | 0.08 | 1.4 | 12 | 0.02 | 0.31 |
| benzene | 0.04 | 0.76 | -1.1 | 9.3 | 0.07 | 0.17 |
| carbon tetrachloride | 0.02 | 0.16 | -0.3 | 7.6 | 0 | 0.04 |
| 12dichloropropane | 0.1 | 0.01 | 10.1 | 38.9 | 0.01 | 0.05 |
| Bromodichloromethane | 0.1 | 0.03 | 21.1 | 88 | 0 | 0.05 |
| trichloroethylene | 0.02 | 0.04 | -4.5 | 58.3 | 0.01 | 0.09 |
| cis13dichloropropene | 0.1 | 0.02 | -11.8 | 56.7 | 0.02 | 0.14 |
| trans13dichloropropene | 0.1 | 0.02 | -11.6 | 56.2 | 0.02 | 0.18 |
| 112trichloroethane | 0.03 | 0 | 10.8 | 45.8 | 0.01 | 0.18 |
| toluene | 0.04 | 1.82 | -4.9 | 14.6 | 0.06 | 0.19 |
| 12dibromoethane | 0.1 | 0.02 | -10.5 | 56.6 | 0.03 | 0.18 |
| tetrachloroethylene | 0.04 | 0.23 | -9.6 | 39.3 | 0.01 | 0.07 |
| chlorobenzene | 0.02 | 0.02 | -30.4 | 83.6 | 0.02 | 0.17 |
| ethylbenzene | 0.02 | 0.27 | 0.5 | 36.5 | 0.03 | 0.12 |
| P/M-xylene | 0.04 | 0.92 | 1.7 | 34.8 | 0.08 | 0.25 |
| Tribromomethane | 0.05 | 0 | -9 | 57.5 | 0.03 | 0.69 |
| styrene | 0.49 | 0.07 | -24.8 | 55.7 | 0.06 | 0.26 |
| 1122tetrachloroethane | 0.2 | 0.01 | -10.3 | 85.5 | 0.02 | 0.12 |
| O-xylene | 0.03 | 0.31 | -6.4 | 25.2 | 0.03 | 0.12 |
| 135trimethylbenzene | 0.26 | 0.12 | -10.1 | 40.7 | 0.03 | 0.18 |
| 124trimethylbenzene | 0.16 | 0.33 | -11.3 | 38.9 | 0.04 | 0.21 |
| a-chlorotoluene | 0.1 | 0.02 | -28.1 | 91.7 | 0.03 | 0.19 |
| 13dichlorobenzene | 0.03 | 0.02 | -32.9 | 76.1 | 0.05 | 0.35 |
| 14dichlorobenzene | 0.04 | 0.09 | -38.5 | 64.3 | 0.06 | 0.55 |
| 12dichlororbenzene | 0.03 | 0.02 | -16.3 | 95.5 | 0.04 | 0.25 |
| 124trichlorobenzene | 0.03 | 0.02 | -22.8 | 75.8 | 0.11 | 0.49 |
| hexachlorobutadiene | 0.1 | 0.03 | 5.5 | 111.5 | 0.06 | 0.36 |
| Compound | MDL PPBv | Avg. Primary Samples | Avg. % Diff. | Standard Deviation | Average Blank PPBv | Max Blank PPBv |
|---|---|---|---|---|---|---|
| dichlorodifluoromethane | 0.02 | 0.63 | 1.0 | 9.8 | 0.007 | 0.055 |
| chloromethane | 0.03 | 0.52 | -3.3 | 19.0 | 0.003 | 0.175 |
| dichlorotetrafluoroethane | 0.03 | 0.02 | 4.1 | 25.1 | 0.005 | 0.03 |
| vinyl chloride | 0.04 | 0.00 | 23.6 | 75.1 | 0.002 | 0.036 |
| 13-Butadiene | 0.04 | 0.08 | 7.4 | 51.0 | 0.006 | 0.055 |
| bromomethane | 0.03 | 0.02 | 0.7 | 39.4 | 0.017 | 0.078 |
| chloroethane | 0.06 | 0.00 | -0.3 | 2.7 | 0.000 | 0 |
| trichloromonofluoromethane | 0.03 | 0.31 | -0.4 | 8.6 | 0.006 | 0.031 |
| 1,1-dichloroethene | 0.02 | 0.00 | 3.0 | 52.8 | 0.005 | 0.031 |
| dichloromethane | 0.02 | 0.15 | -1.2 | 17.1 | 0.011 | 0.117 |
| trichlorotrifluoroethane | 0.02 | 0.09 | 1.5 | 14.1 | 0.007 | 0.04 |
| 1,1-dichloroethane | 0.02 | 0.01 | 1.9 | 58.2 | 0.007 | 0.04 |
| MTBE | 0.03 | 0.87 | 0.4 | 15.3 | 0.002 | 0.036 |
| 2-chloroprene | 0.08 | 0.00 | -2.9 | 24.3 | 0.001 | 0.036 |
| 1,2-dichloroethene | 0.03 | 0.01 | -5.0 | 51.5 | 0.007 | 0.041 |
| chloroform | 0.02 | 0.04 | 2.6 | 32.6 | 0.007 | 0.036 |
| 1,2-dichloroethane | 0.03 | 0.01 | -4.6 | 53.7 | 0.010 | 0.043 |
| 1,1,1-trichloroethane | 0.02 | 0.06 | 0.9 | 11.8 | 0.011 | 0.052 |
| benzene | 0.03 | 0.41 | 0.4 | 8.4 | 0.038 | 0.206 |
| carbon tetrachloride | 0.03 | 0.13 | 1.2 | 8.9 | 0.008 | 0.039 |
| 1,2-dichloropropane | 0.03 | 0.01 | -1.9 | 63.4 | 0.004 | 0.039 |
| Bromodichloromethane | 0.02 | 0.01 | 0.0 | 78.7 | 0.007 | 0.039 |
| trichloroethylene | 0.02 | 0.05 | 3.5 | 38.4 | 0.009 | 0.045 |
| cis 1,3-dichloropropene | 0.03 | 0.01 | -10.3 | 53.8 | 0.010 | 0.048 |
| trans 1,3-dichloropropene | 0.04 | 0.01 | -5.7 | 54.6 | 0.011 | 0.05 |
| 1,1,2-trichloroethane | 0.03 | 0.01 | 2.8 | 32.7 | 0.009 | 0.037 |
| toluene | 0.03 | 0.99 | 0.0 | 8.9 | 0.035 | 0.168 |
| 1,2-dibromoethane | 0.03 | 0.01 | -4.9 | 35.9 | 0.012 | 0.048 |
| tetrachloroethylene | 0.02 | 0.16 | 1.7 | 11.7 | 0.012 | 0.048 |
| chlorobenzene | 0.03 | 0.01 | 2.1 | 23.3 | 0.013 | 0.045 |
| ethylbenzene | 0.06 | 0.16 | 0.6 | 8.7 | 0.021 | 0.085 |
| P/M-xylene | 0.10 | 0.46 | 0.4 | 8.8 | 0.045 | 0.187 |
| Tribromomethane | 0.03 | |||||
| styrene | 0.11 | 0.06 | -1.6 | 27.9 | 0.033 | 0.102 |
| 1,1,2,2-tetrachloroethane | 0.03 | 0.01 | 0.7 | 76.2 | 0.011 | 0.044 |
| O-xylene | 0.04 | 0.16 | 0.7 | 8.6 | 0.020 | 0.081 |
| 1,3,5-trimethylbenzene | 0.05 | 0.06 | 0.8 | 10.9 | 0.018 | 0.084 |
| 1,2,4-trimethylbenzene | 0.05 | 0.17 | 0.7 | 8.3 | 0.026 | 0.169 |
| a-chlorotoluene | 0.04 | 0.01 | 3.4 | 59.0 | 0.012 | 0.052 |
| 1,3-dichlorobenzene | 0.03 | 0.01 | 2.0 | 27.2 | 0.018 | 0.07 |
| 1,4-dichlorobenzene | 0.04 | 0.08 | 2.1 | 13.3 | 0.027 | 0.088 |
| 1,2-dichlororbenzene | 0.03 | 0.01 | 3.3 | 25.3 | 0.018 | 0.05 |
| 1,2,4-trichlorobenzene | 0.03 | 0.01 | 1.5 | 35.2 | 0.029 | 0.222 |
| hexachlorobutadiene | 0.02 | 0.01 | 12.9 | 49.9 | 0.020 | 0.064 |
