Total organic carbon, determination

Solvent extraction combined with chromatographic techniques generally is used to study organic compounds associated with the atmospheric aerosol. Combustion to C02 is additionally used to determine total organic carbon in the samples. This includes elemental carbon present as soot. Due to the limited efficiency of solvent extraction and because many compounds show-... 

According to Radtke et al. (2012), in unconventional reservoirs, integrated capture and inelastic gamma-ray spectroscopy measure carbon accurately, account for inorganic carbon from carbonate minerals, and determine total organic carbon (TOC) . This method is realized in the Schlumberger (2012) study LithoScanner Accurate TOC Determination for Unconventional... 

Organic Carbon. The total organic carbon (TOC) in a water sample is determined by injecting a microliter sample into a heated, packed tube in a stream of oxygen. The water is vapori2ed and carbon is converted to carbon dioxide, which is detected with a nondispersive infrared analy2er. 

Low-temperature ultraviolet-promoted chemical oxidation has provided more reliable and precise data in the determination of low pg/1 levels of total organic carbon [56,78]. 

Table 11.3 presents some typical results obtained by this procedure on seawater samples. MacKinnon [92] concluded that since the volatile organic carbon contents of normal (i.e., unpolluted) seawaters are small, the effect of complete or partial loss of volatile organic components during the determination of total organic carbon in most ocean areas (except highly reducing environments) with either the wet and direct injection methods or dry oxidation methods should be small (about 5%), and within the precision of these methods. 

Soils were further characterized by the determination of pH in water and potassium chloride in the proportions 1 2.5, total organic carbon (TOC) and cation exchange capacity (CEC). Transfer coefficients between soil and plant and enrichment in soils were determined. The results for Pb were represented in the form of relative enrichments for soils (Kabata-Pendias, 1985) and transfer coefficients in plants (Kovalevskii, 1979). 

Schumacher, B.A. 2002. Methods for the determination of total organic carbon in soils and sediments. US EPA Report, NCEA-C-1282, EMASC-001. 

Ratio of microbial biomass to total organic carbon Calculation from individual measures Indicates enrichment of microbial biomass relative to total organic carbon determined in nonstandard laboratory with specialized equipment Rice et al. (1996)... 

Suppliers of visible spectrophotometers are reviewed in Table 1.1. Spectroscopic methods are applicable to the determination of phenols, chlorophenols, amines, mixtures of organics, boron, halogens, total nitrogen and total phosphorus in soils, cationic surfactants, carbohydrates, total nitrogen, phosphorus and sulphur in non-saline sediments, boron, total organic carbon, total sulphur and arsenic in saline sediments, cationic surfactants, adenosine triphosphate and total organic carbon in sludges. 

Infrared spectroscopy has been applied to the determination of particulate organic carbon in non-saline sediments, aliphatic hydrocarbons and total organic carbon in saline sediments and mixtures of organics in sludges. 

This technique has found very limited applications in soil and sediment analysis and is particularly useful when routine automated analyses at the mg L 1 level of large numbers of samples is required. The technique has been applied to the determination of total phosphorus, total organic carbon and total nitrogen in soils, total organic carbon in non-saline sediments and total sulphur in saline sediments. 

Combustion methods have been used to determine total sulphur and total organic carbon and total halides in soil, total and particulate organic carbon, total halide, phosphorus and nitrogen, total and particulate organic carbon in saline sediments and total nitrogen in sludges. 

The DC 180 will calculate total organic carbon based on purgeable organic carbon and non-purgeable organic carbon results and include it in the report. Alternatively, total organic carbon may be determined as the difference of total carbon less inorganic carbon. 

This is a fully automated system capable of determining between lpg L 1 and 300pg L 1 total organic carbon. It is equipped with a 36-place autosampler, microprocessor and printer. Total organic carbon measurements down to 40pg L 1 have been achieved at a coefficient of variation of 16.3%. 

The spectrophotometric method [22] described in section 13.3.2.2 has also been applied to the determination of total organic carbon in sewage sludge. 

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