Over the past century industries have discharged considerable quantities of gas and particle matter into the environment. The legacy this leaves us with is that today we have a number of ex-industrial sites and surroundings impacted by chemical contaminants. Increasing environmental awareness and legislation has lead to new technologies being introduced to monitor emissions and potential harmful effects to the environment.

Sampling methodologies

The sampling of stationery source emissions is a complex procedure due to the variable nature of contaminants and the fact that many compounds can pass through a solution or a solid sorbent without being retained. As a result, sampling trains are optimised with specific solutions or solid sorbents to collect analytes of concern.

Capabilities

Analysis of resulting stack solutions or solid sorbents requires specific methodologies. Following extensive validation, ALS Environmental is able to offer a range of accredited analytical procedures for stationary source emissions based on US EPA, ISO or EN methodologies, as well as for ambient air analysis. Some of our methods are summarized below.

Air Toxic Services

*LOQ in impinger solutions

Metals emissions from stationery sources

Metals emissions are sampled using an impinger train that collects air drawn isokinetically from a stack sampling point. Particulates are collected on sampling probes and heated filters. The gaseous load is collected in an acidified hydrogen peroxide solution. This is effective for all metals except mercury, which is collected in an acidified potassium permanganate solution. Analysis is performed by ICP-OES/MS and AFS (mercury).

Limit of quantification for typical metals determined by this methodology are mentioned below.

Sulphur dioxide emissions from Stationary sources

Gas samples are collected by bubbling air through a hydrogen peroxide solution. Samples are analyzed for SO₂ using a barium-thorin titration method and are reported as mg of SO₂.

HCN, HCl, HF and halogen emissions from Stationary sources

Samples are collected using an impinger train of absorbing solutions, with the use of a pre-filter for determining the particulate load. Samples are analysed using an ion selective electrode (ISE), titration or by ion chromatography (IC). This method of sampling is also often for air quality monitoring in the vicinity of aluminium smelters, power stations, steel works and fertilizer plants.

Hydrogen sulfide emissions from Stationary sources

Samples are collected in a sulfuric acid/silver sulfate solution impinger train and subsequently analysed by photometry. This method is used for a variety of industries including, but not limited to, sulfur recovery plants and fuel gas combustion.

Phenol from Stationary sources

Samples are collected by bubbling air through a sodium carbonates (Na₂CO₃) solution. Samples are analysed by photometry by reaction with 4-aminoantipyrine.

Ammoniac from Stationery sources

Air samples are collected using a solution impinger of sulfuric acid. Samples are analysed by photometry after distillation.

Note: Impinger solution volumes are recorded prior to analysis and are included on the ALS report to enable concentrations to be calculated as mg of analyte per m³.

Volatiles – Emission and ambient air

Samples are collected through sorbent desorption tubes fulfilled with active carbon. The active carbon is then extracted with carbon disulfide (CS₂) and samples are analysed by GC/MS.

Thermal desorption sorbent tubes can be used as well. The extraction is then realized by releasing the compounds using high temperature. More than 100 volatile organic compounds are then determined by the same technique (GC/MS). 

Polyaromatic Hydrocarbons (PAH) – Emission and ambient air

Samples are collected through PUF or XAD trap module. The sorbent (XAD-2 or PUF) is then extracted by organic solvents, pre-cleaned by multiplied column chromatographies, and the final extract is analysed by HPLC or by HRGC-HRMS.

Polychlorinated Biphenyls (PCB) – Emission and ambient air

Samples are collected through PUF or XAD trap module. The sorbent (XAD-2 or PUF) is then extracted by organic solvents, precleaned by multiplied column chromatographies, and the final extract is analysed by HRGC-HRMS. The method is optimised for indicator PCBs (PCB-7), coplanar PCBs (dioxin-like PCBs) and for chlorohomologue groups from mono- to deca- chlorinated biphenyls (All 209 PCBs). 

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) – Emission and ambient air

Samples are collected through a PUF or XAD trap module, sometimes with liquid impingers (glycols). The sorbent (XAD-2 or PUF, glycol) is then extracted by organic solvents, precleaned by multiplied column chromatographies, and the final extract is analysed by HRGC-HRMS. The method is optimized for the 17 most toxic PCDD/F congeners and for chlorohomologue groups from tetra- to octa- CDDs and CDFs (All 210 chlorinated dioxins and furans).

Technical Support - Sampling  

ALS Environmental Europe is working in cooperation with emission and ambient air sampling teams, providing them not only with analytical support, but also prepares sampling chemicals, traps; including chemical blank testing, as well as sampling standards. Traps filled with cleaned XAD or PUF for sampling trains and logistic solutions are also part of our regular services.

A specific portal was created for sampling teams to ease the ordering of laboratory sampling equipment: http://sampling.alsglobal.eu 

For further information on stationary source emission analysis or on ambient air analysis, please contact your nearest ALS location or the ALS Europe Centre for Air analysis in Czech Republic at customer.support@alsglobal.com or +420 226 226 228.