Determination Of Magnesium In Urine Research Articles

Enzymatic Method for the Determination of Magnesium in Urine Using Hexokinase or Glucokinase and Glucose-6-Phosphate Dehydrogenase

Enzymatic Method for the Determination of Magnesium in Urine Using Hexokinase or Glucokinase and Glucose-6-Phosphate Dehydrogenase

An enzymatic method for determining magnesium

The effect of magnesium ions on the catalytic activity of alkaline phosphatases from three different sources in the reaction of p-nitrophenyl phosphate hydrolysis was studied. It was found that magnesium in concentrations of 0.6 ng/mL-20 µg/mL significantly activated alkaline phosphatase from chicken intestine; in higher concentrations (0.02–0.2 mg/mL), it weakly activated the enzyme from E. coli and had no effect on the catalytic activity of the enzyme from the small intestine of the Greenland seal. The strongest activating effect was observed in a Tris-HCl buffer solution at pH 9.8. The activating effect of magnesium on alkaline phosphatase from chicken intestine was used as the basis for developing a highly sensitive and selective enzymatic procedure for determining magnesium (0.6–6.0 ng/mL; RSD = 4% at cmin; n = 5) by spectrophotometrically monitoring the rate of enzymatic reaction. The developed procedure was applied to the determination of magnesium in urine.

A novel method for determination of magnesium in urine and water samples with mercury film-plated carbon paste electrode

A square wave adsorptive stripping voltammetric (SWAdSV) method for the indirect determination of trace amounts of magnesium with thiopentone sodium (TPS) as an electroactive ligand, at carbon paste mercury film electrode (CP-MFE) is proposed. It is observed that the increase of the square wave voltammetric cathodic peak current of TPS, under alkaline conditions, is linear with the increase of Mg concentration. Under optimum experimental conditions viz.; pH 10.75, 3×10−5M TPS and 0.05M phosphate buffer (Na2HPO4–NaH2PO4), a linear relation in the range 6×10−9 to 9×10−8M Mg2+ (0.14–2.16ppb), at 60s deposition time, is obtained. The detection limit of Mg2+ is 0.14ppb for 60s deposition time with the relative standard deviation is 0.5% (n=5). The proposed method was successfully applied to the determination of magnesium in urine and tap water samples with satisfactory results. The data obtained are compared with the standard flame atomic absorption spectrophotometric method (FAAS).

Chelatometrische magnesiumbestimmung im harn

A modification of the complexometric determination of magnesium in urine is described. The method is based on the titration of both magnesium and calcium by using eriochrome black T by indirect titration of the excess of EDTA with magnesium sulfate and then of calcium by direct titration with EDTA on fluorexon. For screening of interfering heavy metals the author used potassium cyanide, triethanolamine hydrochloride in combination with ascorbic acid. The interfering influence of several anions and their removal by exchange with a strongly basic anion exchanger is reported. The results of urine analysis before and after exchange are compared. On the ground of a large clinical material it was found that magnesium occurs in urine in a wide range of concentrations from 33 to 210 mg mg/24 h. The described method was applied for the estimation of magnesium in the urine of patients to whom infusions containing magnesium salts had been given. The method described has proved to be simple, rapid and sufficiently accurate for the routine estimation of magnesium in urine.

A New Rapid Micro=Method* for the Determination of Magnesium in Urine, Without Preliminary Elimination of Calcium

A New Rapid Micro=Method* for the Determination of Magnesium in Urine, Without Preliminary Elimination of Calcium