Volatile Organics Laboratory Analysis
Canisters must be analyzed before the sample degrades. The deadline is 30 days and begins the day the sample is taken. If samples arrive after the deadline, the cans are cleaned for reuse but are not analyzed.
The Gas Chromatograph/Ion Trap Mass Spectrometer (GC/MS) is operated in scan mode. Since this network is for long-term monitoring, the parameters are optimized for linearity and reliability and not set up for maximum sensitivity.
Calibration of the system is performed before, during and after every batch of analyses. The Mass Spectrometer tuning is checked prior to every run. Calibration samples are, at least, analyzed at the beginning, the middle and end of every batch to generate the calibration curve.
The calibration consists of a 15 or 33 liter canister pressurized with CRM level certification gas cylinders. The certified standard is diluted with ultra clean zero air to reduce the 100 ppbv standard to around 5ppbv. The dilution flow is controlled by electronic flow controllers that are accurate to +/-2%. This diluted standard is compared to the NIST traceable PAMS standard. The compounds that overlap in these two standards are used to calculate the dilution ratio. This ratio is used to confirm the true amounts in the diluted standard.
A more detailed description of the analysis is available in the Standard Operating Procedures.
The 44 analytes with the abbreviations, minimum detection levels, and associated Annual Guideline Concentrations (AGC's) as put forth in NYS Air Guide-1 are in Table III.
| CHEMICAL ABBR. |
CHEMICAL | MDL ppb |
AGC* ppb |
EPA AIRS # |
CAS Number |
|---|---|---|---|---|---|
| DCMA | Methylene Chloride(<.3) | 0.2 | 7.8 | 43802 | 75-09-2 |
| CLFM | Chloroform(<.2) | 0.024 | .009# | 43803 | 67-66-3 |
| 12DCA | 1,2 Dichloroethane(<.05) | 0.03 | 0.01# | 43815 | 107-06-2 |
| 111TC | 1,1,1 Trichloroethane(<.2) | 0.024 | 183 | 43814 | 71-55-6 |
| CARBT | Carbon Tetrachloride(<.2) | 0.03 | 0.01# | 43804 | 56-23-5 |
| TCE | Trichloroethylene(<.2) | 0.025 | 0.08 | 43824 | 79-01-6 |
| 112TCA | 1,1,2 Trichloroethane(<.1) | 0.03 | 0.01# | 43820 | 79-00-5 |
| PERC | Tetrachloroethylene(<1.0) | 0.025 | 0.15 | 43817 | 127-18-4 |
| BENZ | Benzene (.05> <5.0) | 0.03 | 0.04 | 45201 | 71-43-2 |
| TOL | Toluene (.5> <5.0) | 0.035 | 106 | 45202 | 108-88-3 |
| EBENZ | Ethylbenzene (.05> <1.5) | 0.06 | 230 | 45203 | 100-41-4 |
| MPXYL | M,P-Xylene (.05> <2.0) | 0.06 | 161 | 45109 | 1330-20-7 |
| OXYL | O-Xylene (.05> <2.0) | 0.04 | 161 | 45204 | 95-47-6 |
| CLBEN | Chlorobenzene(<.1) | 0.03 | 23.9 | 45801 | 108-90-7 |
| ODCBZ | O-Dichlorobenzene(1,2)(<.1) | 0.03 | 60 | 45805 | 95-50-1 |
| MDCBZ | M-Dichlorobenzene(1,3)(<.1) | 0.03 | 60 | 45806 | 541-73-1 |
| PDCBZ | P-Dichlorobenzene(1,4)(<.5) | 0.04 | 0.015# | 45807 | 106-46-7 |
| VINYL | Vinyl Chloride(<.1) | 0.05 | 0.04 | 43860 | 75-01-4 |
| 12DCP | 1,2 Dichloropropane(<.2) | 0.03 | 0.04 | 43829 | 78-87-5 |
| 124MB | 1,2,4-Trimethylbenzene (.01> <1.1) | 0.05 | 59 | 45208 | 95-63-6 |
| 135MB | 1,3,5-Trimethylbenzene (.01> <.05) | 0.05 | 59 | 45207 | 108-67-8 |
| 11DCE | 1,1 Dichloroethene(<.02) | 0.02 | 0.005# | 43826 | 75-35-4 |
| HCBD | Hexachloro-1,3-Butadiene(<.2) | 0.024 | 0.005# | 43844 | 87-68-3 |
| 11DCA | 1,1 Dichloroethane(<.03) | 0.02 | 5 | 43813 | 75-34-3 |
| CLMA | Chloromethane(<2.0) | 0.025 | 373 | 43801 | 74-87-3 |
| CLEA | Chloroethane(<2.0) | 0.06 | 3,790 | 43812 | 75-00-3 |
| c12CE | cis 1,2-Dichloroethene(<.1) | 0.03 | 479 | 43816 | 540-59-0 |
| c13CP | cis 1,3-Dichloropropene(<.1) | 0.03 | 0.04 | 43831 | 542-75-6 |
| t13CP | trans 1,3-Dichloropropene(<.1) | 0.04 | 0.04 | 43830 | 542-75-6 |
| FR12 | Dichlorodifluoromethane (.1> <2.0) | 0.024 | 2427 | 43823 | 75-71-8 |
| FR11 | Trichlorofluoromethane (.05> <1.0) | 0.03 | 3560 | 43811 | 75-69-4 |
| FR113 | Trichlorotrifluoroethane(<.25) | 0.02 | 23488 | 43207 | 76-13-1 |
| FR114 | Dichlorotetrafluoroethane(<.1) | 0.04 | 2,432 | 43208 | 76-14-2 |
| 12BEA | 1,2-Dibromoethane(<.1) | 0.03 | 0.0007# | 43843 | 106-93-4 |
| ACTOL | A-chlorotouluene(Benzylchloride)(<.1) | 0.04 | 0.004# | 45809 | 100-44-7 |
| 1122C | 1,1,2,2 Tetrachloroethane(<.05) | 0.03 | 0.02 | 43818 | 79-34-5 |
| BRMA | Bromomethane(<.1) | 0.03 | 1.29 | 43819 | 74-83-9 |
| STYR | Styrene(<1.0) | 0.1 | 235 | 45220 | 100-42-5 |
| BDCMA | Bromodichloromethane | 0.024 | 0.003# | 43828 | 75-27-4 |
| 13BD | 1,3 Butadiene | 0.04 | 0.01# | 43218 | 106-99-0 |
| MTBE | Methyl Tert Butyl Ether | 0.03 | 834 | 43372 | 1634-04-4 |
| 2CP | 2 Chloroprene | 0.08 | 23.9 | 43835 | 126-99-8 |
| BRFM | Tribromomethane(Bromoform) | 0.03 | 0.09 | 43806 | 75-25-2 |
| 124CB | 1,2,4 Trichlorobenzene(<.3) | 0.034 | N/A | 43810 | 120-82-1 |
# MDL is not low enough to monitor ambient air in concentration range of AGC
* Annual Guideline Concentration
The MDL or Method Detection Limit for this analytical procedure is calculated from 10 or more analytical runs of a standard that contains less than 0.5ppbv of each target compound. The area under the peak for each compound is imported into a spreadsheet and the standard deviation is calculated for this data set. The MDL calculation is 3 times the standard deviation (still in area counts) divided by the average area count of the 10 or more runs times the true concentration in ppbv of the standard used.
* Annual Guideline Concentration
** Minimum Detection Limit -1990-1995 (1995-1998)
