CHESTER LabNet (CLN) provides a wide variety of analytical services, including:
- X-ray Fluorescence (XRF)
- Inductively Coupled Argon Plasma Atomic Emission Spectrophotometry (ICP-AES)
- Ion Chromatography (IC)
- Ion Chromatography Post Column Derivatization (IC-PCD)
- Carbon Analyzer (OC/EC)
- Cold Vapor Atomic Absorption (CVAA)
- Plus a wide variety of wet chemical and gravimetric methods
CLN is intimately familiar with air quality analysis using code of Federal Regulations (CFR) and EPA Inorganic Air Compendium (IO) methods.
Conventional Metals Analysis
Conventional metals analysis includes: Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES or ICP-OES), and Cold Vapor Atomic Absorption (CVAA).
A wide variety of sampling methods are analyzed using these techniques, including but not limited to:
- Hi-vol and Lo-vol filter matrices
- US EPA 40 CFR 60 methods 12, 29, 101A, 103, and 306
- NIOSH 6001, 6009, 7300
- IO 3.1, 3.2, 3.4, and 3.5
X-ray Fluorescence (XRF)
XRF offers rapid analysis of elements (Na through Pb). The typical scan of a Teflon filter includes 38 elements. XRF is an EPA approved, non-destructive analytical method (IO-3.3) wherein a filter is bombarded with X-ray energy. The subsequent excitement of electrons can be measured when the electrons fall back to their valence state, releasing energy in the process. Each element has a “fingerprint” of energy discharges which are measured to determine the quantity of each element.
CLN’s XRF instrumentation is configured for thin-film analyses only (filter deposits).
CLN uses gravimetric techniques for a wide variety of methods, including but not limited to:
- US EPA 40 CFR 50, Appendix B (TSP), J (PM10) and L (PM2.5)
- IO 3.1
- NIOSH 0500 and 0600
CLN has a temperature and humidity controlled weighing room, with a microbalance capable of measuring to one microgram (for small filters), and a balance measuring to 0.1 milligrams (for large filters). The balances are under computer control, and all weighing operations follow the EPA Quality Assurance Guidance Documents 2.11 or 2.12, as appropriate.
Ion Chromatography (IC)
IC is used to determine common anions (F, Cl, Br, NO3, PO4, SO4) and common cations (Na, NH4, K) in various matrices. A wide variety of sampling methods are analyzed using this technique, including but not limited to:
- US EPA 40 CFR 60 methods 7, 13, 26/26A
- CTM027, ST-1B/1A
- NIOSH 6004, 6011, 6014, 6016, 7902, 7903
- US EPA ALT133 for CFR Methods 6 and 8
Ion Chromatography – Post Column Derivatization (IC-PCD)
Cr6+ is analyzed by ion chromatography with post-column derivatization. After separation through the column, Cr6+ forms a complex with diphenylcarbazide (DPC), which is detected at 530 nm. Both ambient air and source samples can be analyzed by IC-PCD.
Chromium is a natural constituent of the earth’s crust and is present in several oxidation states. Trivalent chromium (Cr3+) is naturally occurring, while hexavalent chromium (Cr6+) is anthropogenic. Hexavalent chromium readily penetrates biological membranes and has been identified as an industrial toxin and carcinogen.
Organic Carbon / Elemental Carbon (OC/EC)
OC/EC analysis is a highly specialized thermo-optical method which analyzes for the presence of organic carbon and/or elemental carbon on quartz filters. Typically, total carbon discharges are not monitored as a singular species; rather the specific carbon compound of interest is monitored. For large scale source identification work, OC/EC provides a relatively inexpensive starting point. CLN is capable of analyzing samples by both NIOSH 5040 and the IMPROVE-A method.
Wet Chemistry techniques are used in a variety of analytical methods, most commonly in US EPA 40 CFR 60 methods 6, 7, and 8. Many of the preparatory steps for other methods involve wet chemistry techniques as well. Wet chemistry preparatory techniques may include distillations (M13b), titrations (M6 & M8), biphase extractions (M5F, M202) and more.
Detection limits are determined following NELAP and EPA guidelines where possible. Detection limits, while remaining consistent at the instrument level, may vary depending on the matrix of the sample analyzed.
- Commonly Requested Detection Limits
(Note: the detection limits given here may not be exact. For current detection limits, please contact us.)
CLN prides itself in our ability to work closely with clients to ensure the best data that meets their needs. Although we have listed the most common methods, techniques, and reporting formats on our methods page, we are by no means limited to them. If you have a project related to air quality which may not fall neatly into the methods or techniques we have listed on our site, please contact us.