Analysis of inorganic parameters

George E. Rayment, Ross Sadler, Andrew Craig, 

The electrical conductivity (EC) of a soil suspension provides an estimate of the concentration of soluble salts in the soil in most soils these consist predominantly of the cations Na+, Mg2+ and Ca2+ and the anions Cl-, SO  

Analyte Usual sample size (g)a Extractant Sample/solution ratio Typical extraction time Analytical finish Typical concentration range Expected interlab precision 

PH 10-20 Water or salt solution Define e.g. 1 5 60 minutes Electrode 1-13 CV = 4% 

Soluble chloride (Cl) As for pH Water 1 5 60 minutes Electrochemical Colorimetric IC Colorimetric ICPAES 1-2000 mg/kg CV 10% 

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Rutherford Backscattering Spectroscopy (RBS) is an established technique for analysis of inorganic materials. Recently, several applications of RBS on polymer films have been reported however, the effect of ion beams on these surfaces has not been well documented. RBS has been used to determine fluorine distribution in polymers. Since ion beam irradiation of polymers can induce chemical changes, instrumental parameters need to be optimized to minimize damage. 

Water analysis is mostly conducted using physicochemical methods. A limited number of physical parameters (temperatme, electrical conductivity, redox potential) and test parameters (such as color, smell, and taste) are measured in water analysis. Chemical/ physicochemical methods can be used to analyze for a wide range of components, both inorganic and organic. Spectrochemical or electrochemical methods are mainly used for the analysis of inorganic constituents, while chromatographic methods are applied for the analysis of organic components. 

Brown, I. D. and Altermatt, D. (1985). Bond-valence parameters obtained from a systematic analysis of the Inorganic Crystal Structure Database. Acta Cryst. B41, 244-7. 

An important element in assuring the collected sample representativeness is the use of sample containers that sustain sample integrity. We collect water samples for VOC analysis in 40-ml VOA vials with screw-on PTFE-lined silicon rubber septum caps. The PTFE liner of the septum should always face down to contact the water. Water samples for SVOC analyses are collected into 1-liter amber glass bottles with PTFE-lined lids. Samples for metal and inorganic parameter analysis are placed either into high-density polyethylene (HDPE) or glass bottles. 

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