[Modified method for the rapid determination of the magnesium requirement of cows and sheep]

Korzeniowski's method was modified in preliminary investigations on the semiquantitative determination of magnesium in urine as follows: solution A--citric acid, 6.5 g; 8-oxicholine, 1.8-2.0 g and distilled water up to 100 cm3; solution B--ammonium chloride, 70 g; potassium chloride, 20 g; 25% ammonia, 100 cm3; 96 degrees ethanol, 500 cm3; and distilled water up to 1000 cm3. Prior to work solutions A and B at 1.5 cm3, resp., 6 cm3 were poured in an ordinary cone-shaped or graded centrifugal test tube and were mixed; added was urine for investigation at 5 cm3, the system was stirred and was allowed to stay in a stand for 1 h. If a sediment appeared the amount of magnesium in the urine of cows was above 7 mg%, and in the urine of sheep--above 9 mg%. With the study of a total of 169 urine samples from cows and 74 samples from sheep the results were comparable with what was established via the paper test of De Groot and coll. and the reactive test of Merck. At enhanced diuresis (colourless watery urine with creatine below 20 mg%) false negative results were obtained, and this made it necessary to investigate other samples of urine and blood serum. The method gave favourable information on magnesium sufficiency, and proved suitable for screening work on a mass scale.