The Petroleum Industry is a major source of hydrocarbons – substances known to have impacts on the environment and human health. Traditionally, industry’s focus has been on monitoring a small number of regulated toxic compounds classified as Priority and/or Toxic Substances under Canadian and US Regulations with standards for allowable limits.
As scientific understanding of hydrocarbons grows, two important shifts are occurring: First, while the initial focus has been on a limited number of Parent PAHs, there is a growing realization that Alkylated PAHs (arising from low temperature petrogenic processes) may be even more important than their parents, as they are more persistent, found in higher concentrations, and more toxic. And like the Parent PAHs, since some of these compounds can also occur through the incomplete combustion of organic substances or through natural decomposition processes, analyses needs to be able to differentiate between naturally occurring compounds versus those arising from petroleum-related activities.
Second, the industry and regulatory emphasis is shifting toward fingerprinting and identifying particular sources of a hydrocarbon sample to aid with situations like oil spill examination, accidental contamination and remediation — this is possible since all sources of fossil fuels are slightly different in their proportions of key compounds. To identify sources, however, methods have to move beyond measuring a limited number of parent PAHs to building a profile from a broader set of compound measurements including Parent PAHs, alkylated PAHs, alkanes and hopanes, and naphthenic acids (the latter in particular for oil sands, where processing can magnify these compounds).
SGS AXYS is a leading innovator in the area of hydrocarbon analysis and fingerprinting/forensic examination. AXYS Hydrocarbon methods provides the most extensive list of PAHs and A-PAHs, Naphthenic Acid Isomer Groups, analysis of alkanes (saturated hydrocarbons) and hopanes (pentacyclic compounds) and to enable differentiation of petrogenic and pyrogenic sources of contamination as well as help with pattern recognition, fingerprinting and contaminant source identification during accidental or oil spill investigations or remediation projects. SGS AXYS Hydrocarbon methods are also suitable for low-level baseline or ambient monitoring of each of those compounds:prevnext
Polycyclic Aromatic Hydrocarbons (PAHs) are a group of over 100 different chemicals that consist of two or more fused benzene rings. PAHs are divided into two categories: low-molecular weight compounds, which are composed of fewer than four rings, and high-molecular weight compounds, composed of at least four rings. The solubility and volatility of compounds is related to the number of rings.
AXYS has many years of experience providing quality trace analysis for PAHs by GC-MS in soil, solids, water and biota. AXYS specializes in measurement of PAHs to ultra-trace levels, based on a modified EPA 8270/1625 method which uses incremental deuterium labeled surrogates prior to extraction and subsequent quantification to enhance detection limits and accuracy.
Polycyclic aromatic hydrocarbons (PAHs) containing alkyl side chains are called alkylated PAHs or A-PAHs for short. Nomenclature of A-PAHs includes name of the parent PAH and an indication of the number of carbon in the side chain(s). For instance, all methyl derivatives of naphthalene are called C1-naphthalenes, similarly, all dimethyl derivatives of naphthalene are called C2-naphthalenes, and so on. In general, pyrogenic, or high temperature sources do not favour the formation of A-PAHs. As a result, a relatively high proportion of A-PAHs over parent PAHs in a sample source is an important indication of the PAHs petrogenic origin and vice versa.
Increasing awareness of A-PAHs as rich fingerprinting descriptors, along with the realization that these compounds are present at higher concentrations than their parent equivalents and their toxicity and relative persistence, has highlighted the environmental relevance of A-PAHs. AXYS method MLA-021 has an extensive list of A-PAHs to help with monitoring, fingerprinting and remediation applications.
Alkanes (saturated hydrocarbons) and hopanes (pentacyclic compounds) are present in petroleum sources. Alkanes and hopanes typically accompany PAH analysis, functioning as additional fingerprinting descriptors, and aid in source determination for hydrocarbon fingerprinting projects.
AXYS performs alkane and hopane analyses by GC-MS in water, effluent, solid, sediment, and biosolid matrices. Samples are spiked with a suite of perdeuterated surrogate standards and the solvent is extracted. Alkanes with chain lengths C12 to C36 are analyzed using an isotope-dilution, GC-MS test.
Naphthenic acids (NAs) are of significant interest to all involved in the petroleum industry, particularly in the Oil Sands development.
AXYS has been committed to working with leading organizations in this area of analysis since 2009, developing advanced methods to support Oil Sands monitoring initiatives which balance chemical specificity and analytical cost. Our LC-MS/MS-based Naphthenic Acid methods performed exceptionally well for accuracy and precision of NA water concentrations in Environment Canada’s first multi-method comparison. AXYS has also developed LC-MS/MS method that characterizes NA isomer profiles in soil, sediment and bituminous samples.
Expanded Naphthenic Acid Methods
SGS AXYS has been committed to working with Naphthenic Acids since 2009. To complement our PAH offering, AXYS has developed new analytical methods for monitoring naphthenic acids (NAs) in tissue samples using marker NA isomer peaks that characterizes NA isomer profiles in soil, sediment and bituminous samples and tissues. These methods are suitable for measuring temporal and spatial changes in NA concentration as well as for speciation of NA isomer groups facilitating degradation, accumulation and fate-assessment studies.
SGS AXYS a High-Performing LC-MS/MS-based Naphthenic Acid methods performed exceptionally well for accuracy and precision in Environment Canada’s first multi-method comparison.
Metro Vancouver Multi-Year Project to Study POPS and CECs loading in WWTP and diffusion in the Receiving Environment
AXYS has provided Alkylphenol, Sterols and Hormones, Dioxins, PCB congeners, PAHs, Alkylated PAHs, Pyrethroids, and Organochlorine Pesticides analysis for the characterization of WWTP effluent, storm water/ CSO effluent, and its subsequent diffusion to receiving waters and receiving water sediments. Resident fish are also measured on a scheduled basis.
Analyzing Hydrocarbons in Tissues and SPMDs
Analysis of PAH and alkylated PAH in amphibian tissue and in pond water by SPMD sampling. Speciated naphthenic acid determination in the amphibian tissues.
Driving Deeper Understanding with Alkylated PAHs
Determination of low concentrations and patterns of PAH/alkylayed PAH in muscle tissue of various species of fish from Northern Alberta waters.
Supporting Great Lakes AOC Investigations
AXYS provided analysis for the Great Lakes Area of Concern Investigation, including ambient water, high-volume sampling, precipitation, fish and sediment samples. Axys tested for PAHs, Dioxins, PCBs, OC pesticides including chlorobenzenes, current use pesticides (OC, ON, OP, triazine, pyrethroids), perfluorinated compounds, PBDPE, and PPCPs.
Studying Hydrocarbons with SPMDs
Athabasca River Assessment. Dialysis and PAH and alkylated PAH analysis of 16 SPMDs.
AXYS Innovates to Support Oil Sands Monitoring
Alberta Environment needed to establish baseline conditions for water in Northern Alberta in pristine and oil sands producing areas. AXYS analyzed 240 SPMD samples for PAH and alkylated PAH analysis and 240 POCIS samples for Naphthenic Acids. This study produced data suitable for temporal and geographic tracking and fingerprinting of the PAH, alkylated PAH and naphthenic acids in environmental samples.