Page 181 - An Introduction to Analytical Atomic Spectrometry - L. Ebdon

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2 How does each of these parameters affect the accuracy and precision of the procedure.

3 Report the analytical figures of merit (i.e. limit of detection, linear range, characteristic
concentration) for the magnesium calibration and compare with literature values.

4 Report (with RSD) the result for the concentration of magnesium in the synthetic urine sample and
compare with the normal clinical range.

B.3.6 References

1. Skoog, D.A. and Leary, J.A. (1992) Principles of Instrumental Analysis, 4th edn, 543.08.SKO.

2. Christian, G.D. (1986) Analytical Chemistry, 4th edn, 543.CHR.

3. Alkemade, C.T.J. and Herrmann, R. (1979) Fundamentals of Analytical Flame Spectroscopy, Hilger,
Bristol.

4. Cresser, M. (1994) Flame Spectrometry in Environmental Chemical Analysis: a Practical Guide,
Royal Society of Chemistry, Cambridge.

B.4 Determination of Sodium in Soil Extracts by Atomic Emission Spectrometry
For a given spectrometer it will be necessary to refer to the manufacturer's handbook and instructions
for operation.

B.4.1 Introduction

The major ions in surface and underground waters used for irrigation are Ca , Mg , Na , Cl , SO 42- and
-
+
2+
2+
HCO3- with the relative proportion of sodium to calcium and magnesium having an important effect on the quality of
irrigation water.
If the equilibrium between the exchangeable and solution cations changes so that adsorbed Ca and
2+
Mg ions are replaced by Na , then careful soil management will be required to avoid swelling and loss
+
2+
of permeability, and possibly deflocculation and translocation, when leached with good quality water.
The former process is reversible whereas the latter may lead to an irreversible deterioration of soil
structure. Hence the determination of sodium in soil extracts is an important indicator of soil quality. A
convenient method for the determination of sodium in soil extracts and other aqueous