Volatile organic matter measurement

In this method volatile organic matter in seawater is concentrated on a Tenax GC solid adsorbent trap and dry-ice trap in series. The trapped organic material is then desorbed and oxidised to carbon dioxide, which is measured with a non-dispersive infrared analyser. A dynamic headspace method was used for the extraction with the assistance of nitrogen purging. Dynamic headspace analysis [184] is an efficient extraction procedure. The efficiency of extraction... 

ASTM. 1988. Standard practice for measuring volatile organic matter in water by aqueous-injection gas chromatography - method D 2908-87. In 1988 annual book of ASTM standards. Vol. 11.02. Water II. Philadelphia, PA American Society for Testing and Materials, 46-51. 

Method 25 applies to the measurement of volatile organic compounds (VOC) as nonmethane organics (TGNMO), reported as carbon. Organic particulate matter will interfere with the analysis, and, therefore, in some cases, an in-stack particulate filter will be required. The method requires an emission sample to be withdrawn at a con-... 

Many of the previous direct flux measurements have focused on two distinct ecosystems, intertidal mudflats and Spartina altemiflora salt marshes. These coastal systems have the potential for large emissions of volatile reduced sulfur gases due to the availability of sulfate and organic matter. Intertidal mudflats (3.4) have a tendency towards anoxia, with concomitant production of H S via sulfate reduction. . altemiflora marshes (4T5) release DMS through the... 

All the types of solids described previonsly can have fixed and volatile portions. The fixed portions of the solids are those that remain as a residue when the sample is decomposed at 600°C. Those that disappear are called volatile solids. Volatile solids and fixed solids are normally nsed as measures of the amount of organic matter and inorganic matter in a sample, respectively. Magnesinm carbonate, however, decomposes to magnesinm oxide and carbon dioxide at 350°C. Thns, the amount of organic matter may be overpredicted and the amount of inorganic may be underpredicted if the carbonate is present in an appreciable amount. 

In 2003, urban air pollution was monitored at 76 stations (44 and 32 operated by the Ministry of Health and the Ministry of the Environment, respectively) located in 27 cities involved in the Monitoring System (SZU, 2004). In 2003, sulphur dioxide (SO2), nitrogen oxides (NO/N02/NOx), particulate matter (TSP and/or suspended PMio fractions), and mass concentrations of selected metals (arsenic, chromium, cadmium, manganese, nickel and lead) in particulate matter samples were monitored in all the cities of the Monitoring System except for Melnik. The SO2 measurements in the Public Health Service network were terminated at all the manual stations in the cities with CHMI stations in the cities without a CHMI station, measurements are made during the heating season only). Concentrations of carbon oxide, ozone, polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) continue to be monitored selectively in a number of the monitored cities. 

Many of the basic analytical methods used for determining selenium in biological media are also used for determining selenium levels in soil, water, and air. Precautions in the collection and storage of environmental samples, however, are necessary to prevent loss of the volatile selenium compounds to the air. The destruction of organic matter before selenium measurement is also often necessary. 

Chromium reduction to measure reduced inorganic sulfur compounds in sediments was proposed by Zhabina and Volkov (1978). Since then it has found wide use internationally (Sullivan etal. 1999), particularly when pyritic sediments and acid volatile mono-sulfides are expected. The method is not measurably affected by sulfur in organic matter or sulfates (Canfield etal. 1986 Morse Cornwell 1987). Accordingly, this chromium reducible sulfur method (SCr) is especially useful on samples with appreciable organic matter and also for sandy soils where the %S action criterion is very low (e.g. as low as 0.03%S). 

The relative part of each of these ways of transport depends on the specific properties of the compounds. According to their volatility and water solubility the substances are divided in four main groups (Table 3). As a measure of the affinity of the substances to certain phase (air, water) the partition coefficients octanol/air (log Koa) and air/water (log Kaw) are used. The octanol is used as an equivalent of the organic matter in the environmental media. The substances with low Koa values are volatile, i.e. they have affinity to the air phase, and in the opposite - substances with high coefficient levels have low volatility and do not tend to the air phase. Substances with low Kaw coefficient have higher water solubility and affinity to the water phase, whereas those with higher values of the coefficient have lower solubility in water. 

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