Magnesium in urine

Osis et d. 38) have determined calcium and magnesium in urine, diet, and stool for metabolic studies, and Dennler and Drepper39) have determined calcium and magnesium in the sera of sheep and calves. 

The automated determination of magnesium in urine using o.o -dihyroxyazobenzene (DAB). The final reagent concentrations obtained are ... 

Take an appropriate volume of serum and dilute fifty-fold with lanthanum diluent. For magnesium in urine dilute with lanthanum diluent so that the concentration is about 2 mg/lOOml. 

Several papers deal with magnesium determination in blood and urine. Willis (WIO) analyzed serum in the air-acetylene flame and found no effect from the presence of sodium, potassium, calcium, or phosphate, but states that an enhancement was seen in serum diluted with water only, probably due to serum proteins. This interference was controlled by addition of strontium or EDTA. Sensitivities were the same in the eoal gas-air and air-acetylene flame, indicating complete atomization of magnesium. In urine (W13) no interference was encountered and determinations were performed on samples directly diluted with water. 

W13. Willis, J. B., Determination of calcium and magnesium in urine by atomic absorption spectroscopy. Anal. Chem. 33, 556-559 (1961). 

Caffeine is also a potent stimulant of gastric juice, hydrochloric acid, and pepsin secretion. The serum gastrin concentration may be increased by as much as five times after the ingestion of three cups of coffee. Coffee has a diuretic effect and also increases the excretion of erythrocytes and renal tubular cells in the urine. Caffeine increases the absolute amounts of sodium, potassium, calcium, and magnesium in urine—an effect not observed with decaffeinated coffee. 

Rastegar, F., Maier, E.A., Heimburger, R., Christophe, C., Ruch, C.. and Leroy, M.J.F. (1984). Simultaneous determination of trace elements in serum by energy-dispersive X-ray fluorescence spectrometry, Clin. Chem., 3Q. 1300-1303 Roberts, N.B., Farnclough, D., McLoughlin, S., and Taylor, W.H. (1985). Measurements of copper, zinc and magnesium in urine by DC plasma emission spectrometry, Ann. Clin. Biochem., 22, 533-538... 

The determination of magnesium in urine (Table 3) is helpful in the investigation of hypomagnesemia. If the urinary excretion is increased, hypomagnesemia is probably due to renal insufficiency. However, if the excretion is decreased, an extrarenal cause... 

Farghaly OA (2004) A novel method for determination of magnesium in urine and water samples with mercury fihn-plated carbon paste electrode. Talanta 63 497-501... 

We have found that the use of serum standards for standardizing the instrument in the laboratory is useful. However, the serum standards cannot be used for urines. In urines, one runs into other problems and needs to use aqueous standards. Therefore, at present, while atomic absorption is the instrument of choice, there is much to be desired for the determination of calcium and magnesium in the routine laboratory of clinical chemistry. 

Several recent determinations of the alkali and alkaline earth metals in serum or urine have been reported. Barrett 29) determined potassium, sodium, and calcium in semm by diluting the samples with lanthanum chloride solution. Suttle and Field 3°) used atomic absorption spectroscopy to determine potassium and magnesium in sheep plasma. 

These solid phases are connected to the components in Fig. 4, with which they are in reversible equilibrium. For example, if magnesium ion were added to a complex solution containing solid calcium oxalate monohydrate (COM), the magnesium would compete with calcium for an increased share of the oxalate this would reduce the amount of the calcium oxalate complex, and finally a small amount of calcium oxalate sohd would dissolve to restore the complex concentration to its equilibrium value. In urine, this picture must be extended to account for the molecular substances that coat crystals and reduce access of the solution to the surface coated crystals do not redissolve readily. 

L A. Nephrotoxicity is the most common and most serious toxicity associated with amphotericin B administration. This is manifested by azotemia (elevated serum blood urea nitrogen and creatinine), and by renal tubular acidosis, which results in the wasting of potassium and magnesium in the urine (leading to hypokalemia and hypomagnesemia, requiring oral or intravenous replacement therapy). Normochromic normocytic anemia is also seen with long-term amphotericin B administration. Elevation of hver enzymes is not associated with the use of amphotericin B. 

B.3 Operation and Optimization of an Atomic Absorption Spectrometer and Determination of Magnesium in Synthetic Human Urine. 

To quantify magnesium in synthetic human urine using calibration standards. 

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

The most potent type of diuretic, loop diuretics are named after the loop of Henle, a component of a nephron. The nephrons are the filtering units of the kidney, and are responsible for moving fluids and waste out of the bloodstream, resulting in urine formation. The loop of Henle is a branch within each nephron where sodium and potassium are reabsorbed back into the bloodstream instead of being filtered into the urine. Loop diuretics inhibit this action and promote excretion of the sodium and potassium instead, along with calcium and magnesium. Since excess sodium causes excess fluid build-up, this results in fluid loss. Furosemide (Lasix), bumetanide (Bumex), torsemide (Demadex), and ethacryinic acid (Edecrin) are all loop diuretics. 

Diuretics increase urine and sodium output, and in some cases they may also increase urinary output of potassium, calcium, and magnesium. In large quantities, they can affect electrolyte balance. 

Magnesium sulphate is mostly excreted in urine if urine output falls to below 20 mL/h, the infusion should be stopped. 

At present, uses of Mg are restricted to objectives that can be attained by oral Isotope administration onlyt One of these Is the measurement of "true magnesium absorption in which Mg is given orally, and Mg by Injection. "True absorption Is then computed either by estimation of the ratio %g Mg in urine or, more precisely, by measuring net absorption Csubtractlon of fecal exr ... 

Dawson and Heaton (DIO) determined magnesium in plasma and urine. A water-cooled burner was used with an air-acetylene flame. Good agreement was found with an ammonium phosphate precipitation method when allowance was made for the loss of magnesium during precipitation. 

Stewart et al. (S8) estimated magnesium in serum and urine. Of four different methods of sample preparation (i.e., wet-ashing, deproteiniza-tion, simple dilution with water, and dilution with hydrochloric acid), deproteinization with trichloroacetic acid was found to be most satisfactory. No interference was seen from sodium, potassium, or phosphate, but sulfate produced depression. With protein a 6% decrease in the apparent magnesium concentration was seen. Calcium and sulfate were added to standards and samples to control sulfate depression. 

Horn and Latner (H6) analyzed blood and urine, using an air-propane flame. No interferences were encountered from other serum constituents. The fuel mixture of the flame was found to be critical. Decker et al. (D13) also include data on magnesium in cerebrospinal fluid. 

Dastych M, Jezek P, Richtrova M. Der Einfluss einer PenidUamintherapie auf die Konzentration von Zink, Kupfer, Eisen, Kalzium und Magnesium in Serum und auf deren Ausscheidung in Urin. [Effect of penicillamine therapy on the concentration of zinc, copper, iron, calcium and magnesium in the serum and their excretion in urine.] Z Gastroenterol 1986 24(3) 157-60. 

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