Organic Chemistry

The Australian Water Quality Centre provides analytical services for a wide range of organic constituents in waters and other environmental matrices including algal toxins, disinfection by-products, organic carbon, pesticides, volatile chlorinated compounds (including trihalomethanes), volatile organic compounds, organics of petroleum origin and compounds responsible for tastes and odours in waters. A range of specialised mass spectral analyses is available for the identification and quantification of organic compounds in water. Most analytical methods used are based on internationally accepted procedures (Standard Methods for the Examination of Water and Wastewater, USEPA) and are NATA accredited. A rigorous quality control program ensures the integrity of results.

A comprehensive NATA accredited analytical service is available for drinking water disinfection by-products (DBPs), particularly those listed in the 1996 NHMRC Australian Drinking Water Guidelines (ie. chloroketones, trihalomethanes, haloacetonitriles, chloral hydrate, chloropicrin, chloroacetic acids, chlorophenols, cyanogen chloride, formaldehyde and MX). Analysis for other halogenated DBPs such as bromophenols and brominated haloacetic acids is also available.

The AWQC also holds NATA accreditation for the analysis of Trihalomethane and Chloroacetic Acid Formation Potential, while maintaining an established record of high achievement in DBP analysis and research.

Having assisted the Australian Water Industry in many off-flavour events, the AWQC has built significant expertise in the analysis of off-flavours. It offers a number of techniques for the characterisation of tastes and odours and other organics in a variety of waters including bottled, potable and those used in processing foods.

The AWQC has two GC/MS systems used routinely for the analysis of taste and odours in water. Compounds such as 2-methylisoborneol (MIB) and geosmin which are responsible for earthy/musty and earthy/grassy odours in water are determined by Closed Loop Stripping Analysis (CLSA) using gas chromatography-mass spectrometry. This method has been developed to provide precise and accurate quantification of these compounds to 1 nanogram per litre (1 ppt), which is well below the human odour threshold for these compounds. 2,4,6-trichloroanisole or TCA is also analysed in a similar manner (detection limit: 0.2 ng/L).

The AWQC can provide a fast turn around time of no more than 24 hours for these tests, allowing a rapid response to operational taste and odour problems.

Other taste and odour compounds quantitatively analysed include halogenated phenols. The methods used are readily extended for complete screening of other odorous compounds which may be present in water.

The AWQC provides a full scan GC/MS analysis for qualitative taste and odour determination in troubleshooting off-flavour problems in a wide variety of waters.

The AWQC has an excellent record in algal toxin analysis and research. It provides a rapid service for the quantitative determination of toxins produced by algal blooms and has assisted the water industry in this area throughout Australia and also overseas.

LC/MS is utilised for the determination of a wide range of algal toxins. Quantitative analyses for microcystins, anatoxin-a, nodularin, paralytic shellfish poisons (PSP), and cylindrospermopsin are available. The AWQC is also NATA accedited for the analysis of ochratoxin-a in wines and beers.

The AWQC has recently achieved NATA Accreditation for microcystins and nodularin analysis.

Organic carbon (total and/or dissolved) analyses are
carried out, using NATA accredited methods, by determining the carbon dioxide produced from oxidation of the organic carbon present following removal of the inorganic carbon. Samples containing low levels of organic carbon (<25 mg/L, eg. potable waters) are analysed using a heated persulphate oxidation procedure with detection of the carbon dioxide with a non-dispersive infrared analyser. The reporting limit is 0.3 mg/L.

Samples with higher concentrations (eg. wastewaters) are analysed using high temperature (950°C) oxidation with measurement of the carbon dioxide produced with a non-dispersive infrared analyser.

Volatile chlorinated hydrocarbons, such as trihalomethanes, carbon tetrachloride, 1,1,1-trichloroethane, tri- and tetrachloroethylene and tetrachloroethane are analysed by Purge and Trap GC/MS. This NATA accredited test offers detection limits of 1 ug/L and is available as part of the VOC scan.

Pesticides including organochlorine insecticides, organophosphorus insecticides and triazine herbicides are determined in a wide range of waters by NATA accredited methods. The organochlorine screen covers lindane, aldrin, chlordane a + d, chlorthalonil, chlorpyrifos, dieldrin, endrin, heptachlor and its epoxide, DDT and metabolites, endosulfan 1 + 2 and its sulphate, methoxychlor, trifluralin, viclozolin and the herbicide chlorthal dimethyl (dacthal). Analysis is carried out by gas chromatography using electron capture detection. Report limit for most pesticides is 0.01mg/L. Other pesticides can be included if amenable to analysis by this procedure.

The organophosphate and triazine screen covers malathion, azinphos-methyl, diazinon, fenitrothion, parathion, parathion-methyl, atrazine, simazine, hexazinone and prometryne with report limits of 0.5 ug/L. Analysis is carried out using solid-phase extraction followed by gas chromatography with thermionic specific detection. Other organophosphorus insecticides can be included if amenable to analysis using this procedure.

Other pesticide screening services include chlorsulfuron, clopyralid, dicamba, 2,4-D, 2,4,5-T, metsulfuron methyl, MCPA, picloram, silvex, sulfometuron, trichlopyr, fipronil and its metabolite fipronil-desulfinyl. The AWQC also offers analysis for atrazine and atrazine metabolites, by LC/MS with reporting limits of 0.1 ug/L and has recently incorporated temephos and glyphosate into its range of available analyses.

Method development / validation may be conducted on request for other pesticides not listed here.

The Volatile Organic Compounds (VOC) scan covers over sixty compounds including monocyclic aromatics, halogenated aliphatics and halogenated aromatics. Purge and Trap GC/MS is employed for the analysis of these compounds. The AWQC holds NATA accreditation for this test.

Petroleum Hydrocarbons & Fuel Additives

Analysis for aromatic hydrocarbons (the BTEX group - benzene, toluene, ethylbenzene and xylenes) is available as part of the VOC scan or as a discrete test. This test provides reporting of individual compounds to 1ug/L. Analysis for diesel and the fuel additive MTBE (Methyl Tertiary Butyl Ether) is also available.

Haloganated Phenols

Chlorinated & brominated phenols are determined by derivatisation followed by solvent extraction and GC/MS. Compounds covered include 2- chlorophenol, 4- chlorophenol, 2,4-di, 2,6-di, 3,5-di, 2,4,5-tri-, 3,4,6-tri, and pentachlorophenol, as well as the brominated phenols 2- bromophenol, 3- bromophenol, 4- bromophenol, 2,4-di, 2,6-di, and 2,4,6- tribromophenol. This test provides a reporting limit of individual componds to 0.1mg/L.

GC/MS (EI, NCI), single quadrople
GC/MS/MS (ion trap)
LC/MS/PDA
GC/ECD
GC/TSD
Headspace GC/ECD
Purge & Trap GC/MS
HPLC/FLD
HPLC/FLD post column derivatisation system
TOC/DOC Wet oxidation analyser
TOC/DOC High temperature combustion analyser

Closed Loop Stripping Analysis
Solid Phase MicroExtraction (SPME)
Solid Phase Extraction (SPE)
Solvent extraction
Immunoaffinity Columns

The AWQC has modern sophisticated instrumentation used for the analyses of organics in water and other matrices. LC/MS, GC/MS with Purge & Trap, GC/MS GC/MS/MS enable a wide range of testing.
Please contact the AWQC to discuss more specialised analyses; for example:

- pesticides
- tastes and odours
- identification of hydrocarbons present in oil spills,
wastewaters and drains
- environmental incidents
- natural products (eg. terpenes) from plants, algae
and wood extracts
- algal toxins
- ochratoxin-a analysis in wines, beers, and grape juice.
- identification of general organics (PAHs, PCBs, TRH, AOX)
- F.A.M.E. (Fatty Acid Methyl Esters)
- Faecal Sterols