scholarly journals Simultaneous Determination of Sodium and Potassium in Small Volumes of Fluid by Flame Photometry

1953 ◽  
Vol 30 (1) ◽  
pp. 1-17
Author(s):  
J. A. RAMSAY ◽  
R. H. J. BROWN ◽  
S. W. H. W. FALLOON
Keyword(s):  
Standard Deviation ◽  
Simultaneous Determination ◽  
Biological Fluids ◽  
Ammonium Phosphate ◽  
Flame Photometry ◽  
Limits Of Detection ◽  
Other Substances ◽  
Lower Limits ◽  
Sodium And Potassium

1. A method of flame photometry is described, by which the amount of sodium and potassium in biological fluids can be determined simultaneously, using samples of the order of 10-3 cu.mm. 2. When the method is tested with quantities near the lower limits of detection (of the order 4 x 10-8 mg. sodium, 6 x 10-8 mg. potassium) the reproducibility, measured as standard deviation, is ±7 x 10-9 mg. sodium and ± 17 x 10-9 mg. potassium. 3. When larger quantities (up to certain limits) are used, the standard deviation is approximately ± 3 % of the quantity in the sample, both for sodium and for potassium. 4. As is usual in flame photometry serious errors can be caused by the presence of other substances in the sample. In the case studied for purposes of illustration it is shown that these interference errors can be reduced to the order of ± 6 % by the addition of excess ammonium phosphate.

The Determination of Sodium in Small Volumes of Fluid by Flame Photometry

1950 ◽  
Vol 27 (3) ◽  
pp. 407-419 ◽  
Author(s):  
J. A. RAMSAY
Keyword(s):  
Sodium Chloride ◽  
Biological Fluids ◽  
Systematic Errors ◽  
Flame Photometry ◽  
Average Error ◽  
Other Substances

1. A method of integrative flame photometry is described, by which the amount of sodium in biological fluids can be determined, using samples of the order of 10-3 cu.mm. 2. With pure solutions of sodium chloride, of concentration from 0.05 to 2.0 %, the average error of the method is about 3 % of the concentration. 3. When other substances are present systematic errors of up to 7.7 % have been recorded. 4. The possibilities of reducing these systematic errors and of extending the method to deal with other elements are discussed.

scholarly journals ELECTROMETRIC TITRATION OF CHLORIDE IN SMALL VOLUMES

1955 ◽  
Vol 32 (4) ◽  
pp. 822-829 ◽  
Author(s):  
J. A. RAMSAY ◽  
R. H. J. BROWN ◽  
P. C. CROGHAN
Keyword(s):  
Standard Deviation ◽  
Silver Nitrate ◽  
Biological Fluids ◽  
Silver Electrode ◽  
End Point ◽  
Other Substances ◽  
Electrometric Titration ◽  
In Series ◽  
A Current

1. Two methods of titrating chloride with Ag+ ion using the potentiometric end-point are described. 2. The first method is conventional in that silver nitrate is added from a burette. It deals with volumes down to 0.2µl. and can measure 1µg. of chloride with an error of < ± 1% (standard deviation). 3. According to the second method Ag+ ion is added by passing a current through a silver electrode in series with a condenser. The charge developed on the condenser is a measure of the amount of chloride titrated. This method deals with volumes down to 0.5 x 10-3µl. and can measure 10-4µg. of chloride with an error of < ± 1% (standard deviation). 4. As far as is known these methods are not susceptible to interference from other substances likely to be present in biological fluids.

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