Methodologies for the analysis of petroleum hydrocarbons extracted from contaminated soils

Australian research into TPH and BTEX test methods has, to date, not been coordinated and no standard methods have been agreed to. Overseas research also lacks acceptable solutions for the standardisation of TPH and BTEX methodologies. Since Australia carries out many thousands of analyses of TPH and BTEX on contaminated soils annually research into and assessment of current methods is required to demonsfrate the effects on outcomes of method choice. In the Australian context the problem of developing standard methods for the analysis of hydrocarbon contamination of soil, and establishing a more scientific basis for commercial operations has been addressed in this thesis. In particular, problems associated with establishing TPH and BTEX analysis have been critically examined with a view to exposing shortcomings and suggesting possible solutions. The study includes an assessment of the relationship between measurements in the field and in the laboratory for TPH (C6-C9) and BTEX; an area where there are known to be frequent disagreements. This study confirms this problem and aims to educate practitioners of the limitations of field measurement

Modes of handling Oxygen Radical Absorbance Capacity (ORAC) data and reporting values in product labelling

Antioxidant measurement assays are widely used and should be chosen based on their being fit for purpose. Likewise, the mode of reporting antioxidant measurements should also be fit for purpose. The Oxygen Radical Absorbance Capacity (ORAC) assay is widely used internationally for measuring the antioxidant capacity of commodities using the peroxyl radical. However, the current mode of reporting of the ORAC values is not obvious, especially for the consumer groups. In this mode, reporting of the ORAC values is the unit of micromoles of vitamin E analogue (VEA), known commercially as Trolox Equivalents per kilogram or per litre (μM T.E./kg or L). Unlike mass units, molar units are not widely used in nutrition information panels (NIP). This paper presents a simple mathematical model for conversion of ORAC values to mass units to facilitate better understanding of the antioxidant capacity quoted. Additionally, mass values are in keeping with current labelling practice in Australia. Unless legislation is passed for the regulation of ORAC data use in labelling and product marketing, mass units should be considered as a mode of reporting, limiting sensationalism of antioxidant capacity and keeping with current labelling practice

Symposium no. 41 Paper no. 1965 Presentation: oral 1965-1

The USEPA SW-846 series of methods, and variations (validated) thereof, for the analysis of TPH contamination in soil have been used to test the dependence of measured TPH levels on method variation in a series of carefully controlled and statistically rigorous experiments. For example, the importance of using a common method, that minimizes evaporative loss, for the simultaneous determination of volatile TPH (C 6 -C 9 ) and BTEX by either gas chromatography flame ionisation detection (GCFID) or by gas chromatography mass selective detection (GCMSD), has been demonstrated. For general TPH analysis, the importance of using baseline-to-baseline rather than peak-to-peak integration is emphasized. Choice of an appropriate calibration standard for volatile TPH has been discussed, and experimental evidence is provided to support the use of n-octane (n-C 8 ) over BTEX or a BTEX/n-C 8 mixture , for both P&T/GCFID and for P&T/GCMSD. For the determination of semi-volatile TPH (C 10 - C 36 ) by a given method, varying the extractant solvent (neat dichloromethane (DCM), 1:1 v/v DCM/acetone or isopropanol), the extraction method (sonication versus soxhlet) and detector type (GCFID versus GCMSD), shows that statistically significant variations in TPH measurements can arise with each type of variation. Therefore, it is concluded that for typical soil samples, standardisation (and optimisation) of method, is an important ongoing issue in efforts to provide a more scientific basis for the measurement of TPH contamination in soil

Concentrations of contaminants (mg/kg wet weight) in blubber from individuals of <i>Tursiops australis</i> from Victoria, Australia.

<p>Values shown are means with standard errors and range in brackets underneath.</p

Concentration of total mercury (mg/kg wet weight) in blubber and liver from live and dead individuals of <i>Tursiops australis</i> from Victoria, Australia.

<p>Values shown are means with standard errors, sample sizes are shown in brackets above each bar. Values marked * were estimated from a regression between liver and blubber levels from worldwide levels.</p

Biological characteristics of beach cast individuals of <i>Tursiops australis</i> from Victoria, Australia.

<p>Biological characteristics of beach cast individuals of <i>Tursiops australis</i> from Victoria, Australia.</p

Symposium no. 41 Paper no. 1965 Presentation: oral 1965-1

The USEPA SW-846 series of methods, and variations (validated) thereof, for the analysis of TPH contamination in soil have been used to test the dependence of measured TPH levels on method variation in a series of carefully controlled and statistically rigorous experiments. For example, the importance of using a common method, that minimizes evaporative loss, for the simultaneous determination of volatile TPH (C 6 -C 9 ) and BTEX by either gas chromatography flame ionisation detection (GCFID) or by gas chromatography mass selective detection (GCMSD), has been demonstrated. For general TPH analysis, the importance of using baseline-to-baseline rather than peak-to-peak integration is emphasized. Choice of an appropriate calibration standard for volatile TPH has been discussed, and experimental evidence is provided to support the use of n-octane (n-C 8 ) over BTEX or a BTEX/n-C 8 mixture , for both P&amp;T/GCFID and for P&amp;T/GCMSD. For the determination of semi-volatile TPH (C 10 - C 36 ) by a given method, varying the extractant solvent (neat dichloromethane (DCM), 1:1 v/v DCM/acetone or isopropanol), the extraction method (sonication versus soxhlet) and detector type (GCFID versus GCMSD), shows that statistically significant variations in TPH measurements can arise with each type of variation. Therefore, it is concluded that for typical soil samples, standardisation (and optimisation) of method, is an important ongoing issue in efforts to provide a more scientific basis for the measurement of TPH contamination in soil