Inorganic compounds determination, water samples

The determination of inorganic compounds in water samples provides significant data for risk assessment in aquatic environments and for characterizing the chemical quality of water. The presence of inorganic chemicals in water is due to both natural processes and human activities. Most of these... 

In conclusion, for determination of inorganic compounds in water, reliable sampling processes are necessary, followed by spectrometric techniques that assure low detection limits as well as good selectivity and reliability of analytical information. The rapidity and reliability of the spectrometric methods proposed for inorganic compound assay in water caused them to be used in a flow injection system with good results. Through utilization of these methods in flow injection systems, an increase in reliability of the analytical information was achieved. 

The determination of dissolved organic carbon by oxidation methods in water comprises three analytical steps the removal of inorganic carbon from the sample, oxidation of the organic compounds to carbon dioxide, and the quantitative determination of the resulting carbon dioxide. The methods of oxidation can be classified into three major groups ... 

Matrix spike/matrix spike duplicate Organic and inorganic compounds recovery as determined by laboratory control charts precision of 30% for water and 50% for soil is typical for environmental samples ICP-AES 75 to 125% recovery 20% precision AA 80 to 120% recovery 20% precision... 

The unique aspects of speciation procedures arise from the additional specification that the procedure adopted should not disturb existing equilibrium conditions. The choice of procedure is further restricted by the fact that the total concentration of element present in a sample (e.g. Cu, Pb, Cd, Zn in water samples) is often near the detection limits of many standard analytical techniques, and modified or refined techniques are required to handle the even lower levels present in isolated sub-categories. In biological matrices, the concentrations of inorganic and organo-metallic compounds present can range from 10 3 to 10 12 mol dm 3, and at the lower levels even the determination of total element content can be greatly in error, if suitable correction is not made for interference effects which can arise from the nature of the sample. 

Preservation of Water Samples for the Determination of Inorganic Compounds. .. 19... 

PRESERVATION OF WATER SAMPLES FOR THE DETERMINATION OF INORGANIC COMPOUNDS... 

In Table 1.3.2 a method for the analysis of nitrates and nitrites for a wide variety of samples is given Aqueous nitrate ions are converted to nitrobenzene by reaction with benzene in the presence of concentrated sulfuric acid as catalyst. The special methods for the different materials are described. To stabilize samples against bacterial action, which can reduce nitrate concentrations, phenylmercuric acetate is added after collection ° Other inorganic compounds in the trace levels for gas-chromatographic determination are, for example, water and carbon monoxide, which were determined in organic solvents or air in the ppb-range ... 

Pozzi et al. used a dynamic headspace method in combination with a mobile ion mobility spectrometer for the determination of MTBE in drinking water and groundwater [68]. The analytes were sorbed on a Tenax trap cooled with liquid nitrogen, placed between the sample bottle and the IMS. An on-line method for the determination of MTBE and BTEX from groundwater samples was developed by Borsdorf et al. [69]. In this study, an extraction chamber with a membrane was used for the extraction of MTBE from the aqueous phase with a detection limit of 12 xgL Neither inorganic compounds nor humic substances affected the peak intensity of MTBE significantly. 

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