Comparison of Methods for the Determination of Total Phosphorus in Waters Containing Particulate Material

1975 ◽  
Vol 4 (3) ◽  
pp. 347-350 ◽  
Author(s):  
P. W. O'Connor ◽  
J. K. Syers
1979 ◽  
Vol 62 (1) ◽  
pp. 153-159
Author(s):  
Luis F Corominas ◽  
Victor M Boy ◽  
Manuel Guijosa

Abstract The official first action AOAC method for the spectrophotometric determination of biuret in urea, 2.072—2.074, was compared with official first action AOAC method 2.C01-2.C03 (atomic absorption spectrophotometry), 2 simplified versions of 2.072-2.074, and modified versions of 2 alternative procedures of the International Organization for Standardization. Three synthetic urea samples (0.3, 1.4, and 3.0% biuret) and 1 commercial urea sample (1.0% biuret) were analyzed. The methods proved to be equivalent and none showed a definite advantage over 2.072-2.074. The purification of biuret and the interference by ammonia are also discussed.


1962 ◽  
Vol 8 (6) ◽  
pp. 598-605 ◽  
Author(s):  
Yung S Shin ◽  
James C Lee

Abstract A method is presented for the determination of cholesterol and phospholipid, which requires 5 µl. of human serum or 1-2 ml. of cerebrospinal fluids. With this method 5-100 µg. of cholesterol and phospholipid can be separated by a modified silicic acid column after elution of the mixture with 1 ml. of chloroform and 3 ml. of methanol. Recovery for 24.6 µg. of cholesterol and 30.5 µg. of phospholipid was 98.4 and 96.7%, respectively. Standard deviations of ± 1.73 and ± 1.24 have been obtained for the reproducibility of cholesterol and phospholipid determinations after chromatography. The method has been applied for the estimation of the cholesterol/phospholipid ratio and of lipid phosphorus in total phosphorus of human cerebrospinal fluids.


1947 ◽  
Vol 19 (5) ◽  
pp. 336-337 ◽  
Author(s):  
W. W. Bowler ◽  
E. A. Arnold

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