Flow Injection Determination of Sodium, Potassium, Calcium, and Magnesium in Beer by Flame Emission and Atomic Absorption Spectrometry

Abstract

Flow injection systems for the determination of sodium and potassium, by flame emission photometry, and calcium and magnesium, by atomic absorption spectrometry, in beer are described. The samples were directly injected in the flow system where automatic dilution occurred, and reagent addition using the merging zones technique was performed. Lanthanum(III) consumption was reduced in about 20−80-fold compared to conventional manual atomic absorption determinations. Sampling rates of 120−200 determinations/h were achieved. The results were in agreement with the reference procedures (relative deviations below 3.8%) and present good reproducibility (relative standard deviations lower than 1.6% for 10 consecutive measurements). Keywords: Flow injection; beer; Na; K; Ca; Mg; flame emission; atomic absorption spectrometry

A Data Mining Approach to Improve Inorganic Characterization of Amanita ponderosa Mushrooms

“…Sodium (Na) and potassium (K) were quantified by flame emission photometry with a Jenway model PFP7 flame emission photometer [ 30 , 31 ]. Phosphorus (P) was quantified by vanadomolybdophosphoric acid colorimetric method, using a spectrophotometer (Hitachi, U-3010 model) [ 32 ].…”

Determination of Calcium in Powdered Milk via X-ray Fluorescence Using External Standard and Standard Addition Based Methods

“…Determination of calcium (Ca) in water, milk, and biological samples is a popular experiment in many chemistry laboratory classes and can be achieved using a number of methods including EDTA titration, ion selective electrodes (ISEs), or flame atomic absorption spectrophotometry (FAAS). EDTA titration is perhaps the most commonly used method, requiring basic laboratory equipment (i.e., balances and burets), but is nonselective and typically requires several lab periods for preparation, standardization, and analysis of the different solutions. , A potentiometric method based on use of an ISE is faster, more sensitive and selective, and is unaffected by color or turbidity. , FAAS requires more expensive instrumentation and is even more sensitive and selective. , …”

“…3,4 FAAS requires more expensive instrumentation and is even more sensitive and selective. 5,6 Energy-dispersive X-ray fluorescence (hereinafter referred to as XRF unless otherwise noted) is a selective and rapid means for quantifying Ca but ideally requires a set of standards that closely approximate the sample matrix to achieve accurate quantification. A number of references document the use of XRF for determination of Ca in milk, 7−9 each of which used a pellet press to prepare samples and different methods to calibrate instrument response.…”