Thoroughly clean and rinse all glassware with the supplied BWB Technologies deionised distilled water to ensure that it is clean and free of extractable sodium and potassium. Glassware should be acid cleaned and rinsed thoroughly in deionised double distilled water prior to use to avoid contamination from extractable metals under test.
The use of lithium carbonate for the treatment of bipolar disorders and depression is well established. However, for the treatment to be effective, it must be managed closely, to ensure the dose is maintained within the normal therapeutic range.
The calcium content of aqueous solutions of deoxyribonucleic acid (DNA) and deoxyribonucleoprotein (DNP) can not assayed directly because of interference effects. An acid extraction procedure will enable direct measurements of calcium in DNA and DNP, or a standard addition technique is used at higher concentrations.
Several different techniques can be used for sample digestion and extraction of sodium and/or potassium: oven ashing, perchloric acid ashing, extraction by boiling and acidification with HNO3 as well as extraction by homogenisation in 2% trichloroacetic acid (TCA).
This technique allows use of aqueous standards for calibration rather than relatively unstable organometallic standards and harmful solvents for the extraction Microemulsions are thermodynamically stable systems composed of water, oil and surfactant. In some cases an alcohol is added as a co-surfactant.
The effect of potential interference from other constituents of sea water was studied, including sodium, chloride and potassium. It was found that pre-concentration of the sea water was not necessary prior to analysis. A filtration of the sample was only necessary if sample contained suspended material.
A number of methods have been reported for the measurement of calcium in biological materials by flame photometry or titration. This method employs trichloroacetic acid (TCA) to precipitate the proteins and has been found to be adequate to extract all of the calcium from tissue samples. Sodium, potassium and phosphate caused no significant interference and calcium concentration in the range of 0 to 2 µg/ml is readily determined.
Commercial cereals vary considerably in composition, both in their formulation and the ingredients added to enrich these products. Sodium is the predominant cation in breakfast cereals, at levels reaching 8mg/g. Potassium and calcium also vary, particularly in wheat-based products and those enriched with milk products or calcium salts.
This method reduces or removes potential interference from sodium, potassium and phosphates normally present in serum and urine by diluting the samples with a diluent containing ethylenediaminetetraacetic acid (EDTA). There was no effect from the presence of dissolved proteins on the calcium signal; the protein remains in solution when the serum is diluted with ≤0.15M EDTA. Prepared diluted samples contained 0.1-0.3mEq/l of calcium in urine and 1-3mM/l in serum, with an accuracy of ± 0.1mEq/l .
These methods are adapted from methods for the determination of sodium and potassium in fatty-acid methyl ester samples. The sample is diluted with an organic solvent (xylene, cyclohexane or petroleum ether) plus a stabiliser.
Bread contributes about one-sixth of daily salt intake and is used to improve flavour and texture. The amount of sodium in bread can differ significantly, depending upon brand and type of grain used, ranging from 592mg/100g to 748mg/100g.
This method for the measurement of sodium and potassium in silicate rocks uses a borate fusion technique.The sample is fused with a suitable fusion agent such as boric acid (H3BO3) and lithium carbonate (Li2CO3) and the ground product is dissolved in dilute citric acid.The presence of other metals such as aluminium, calcium, iron, magnesium and silicon should not interfere with the measurement of sodium or potassium using this method.
Molarity is probably the most commonly used unit of concentration. It is the number of moles of solute per litre of solution (not necessarily the same as the volume of solvent). The SI unit of molarity is mol/dm3