BWB Technologies Ltd. applications

The calcium content of aqueous solutions of deoxyribonucleic acid (DNA) and deoxyribonucleoprotein (DNP) cannot assayed directly because of interference effects. An acid extraction procedure enabled direct measurements of calcium in DNA and DNP, or a standard addition technique was used at higher concentrations.

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.

This method has been adapted to enable measurement of lithium over a wide range of concentrations (0.10 to >8.0%), in lithium containing materials.

This method allows the direct measurement of low levels of sodium without prior extraction procedures, which minimises possible sources of contamination.

This method allows the analyte to be pre-concentrated in the final solution, decreases the volume of strong acid used in the dissolution stage and does not use organic solvents.

The sample of biodiesel is weighed into a crucible and placed in a heating muffle furnace. Two temperatures are used in the heating program for the dry decomposition: the first temperature (250ºC) is maintained for 1 hour to dry the sample. After this the temperature is progressively elevated to 600ºC and maintained for 4 hours to eliminate the remaining organic material.

Sodium chloride is an essential ingredient of all processed foods; it is needed to enhance flavour and increase shelf life. In many processed foods, additional sodium is added as a flavour enhancer; potassium and calcium are also naturally present but not normally used as processing additives.

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.

In most cases, it was found that flame photometry was well suited for the determination of sodium, potassium and calcium in fresh fruits, using the wet ashing technique as given below. There are significant differences in the composition between different varieties of the same fruit, although these differences are not usually considered to be nutritionally significant.

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).