Direct Measurement of Chloride in Sweat with an Ion-Selective Electrode

1973 ◽  
Vol 19 (7) ◽  
pp. 727-730 ◽  
Author(s):  
LaVerne Szabo, Margaret ◽  
A Kenny ◽  
Winnie Lee
Keyword(s):  
Direct Measurement ◽  
Chloride Concentration ◽  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Sweat Chloride ◽  
Insufficient Amount ◽  
Chloride Concentrations

Abstract The use of a specific ion electrode for measuring sweat chloride has not been widely accepted because of poor precision and occasional falsely elevated chloride concentrations. We have studied this technique by using the Orion sweat-chloride instrument, and have eliminated these problems by modifying the methodology. An insufficient amount of sweat for determination with the electrode was responsible for both the imprecision and random inaccuracies. The following modifications eliminated these problems: (a) We freshly saturate felt pads with a solution of, per deciliter, 400 mg of pilocarpine nitrate and 1 g of NaHCO3 to replace the electrolyte pads supplied by the Orion Co. (b) The timed iontophoresis period commences after the meter indicates conduction of adequate current. (c) After iontophoresis, sweat is collected for 10 min under a plastic cap held over the induction area. Then chloride concentration is measured with the electrode. With these improvements in technique, the revised procedure should be as reliable as reference methodologies.

Effect of temperature on response of the sweat chloride ion-selective electrode.

1982 ◽  
Vol 28 (12) ◽  
pp. 2447-2448 ◽  
Author(s):  
R G Benson ◽  
D M Isherwood ◽  
F A McEvoy ◽  
A Wood
Keyword(s):  
Chloride Ion ◽  
Ion Selective Electrode ◽  
Effect Of Temperature ◽  
Selective Electrode ◽  
Sweat Chloride

Direct measurement of Cu(II)aq in seawater at pH 8 with the jalpaite ion-selective electrode

1998 ◽  
Vol 61 (3-4) ◽  
pp. 173-184 ◽  
Author(s):  
Alberto Zirino ◽  
David A. VanderWeele ◽  
Stuart L Belli ◽  
Roland DeMarco ◽  
Denis J Mackey
Keyword(s):  
Direct Measurement ◽  
Ion Selective Electrode ◽  
Selective Electrode

Evaluation of a cystic fibrosis screening system incorporating a miniature sweat stimulator and disposable chloride sensor.

1986 ◽  
Vol 32 (5) ◽  
pp. 850-853 ◽  
Author(s):  
W J Warwick ◽  
N N Huang ◽  
W W Waring ◽  
A G Cherian ◽  
I Brown ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Chloride Concentration ◽  
Test System ◽  
Sweat Test ◽  
Sweat Chloride ◽  
The Subject ◽  
New System ◽  
Chloride Concentrations ◽  
Cystic Fibrosis Screening ◽  
Center Study

Abstract A new sweat test (CF Indicator; Medtronic, Inc.) for cystic fibrosis (CF) features a compact, portable configuration of electrodes that dispense pilocarpine for iontophoresis. A disposable chloride sensor patch absorbs a specified volume of sweat, in which the chloride concentration is immediately determined as less than 40, 40-60, or greater than 60 mmol/L. We assessed the performance of the system in a five-center study, in relation to the clinical diagnosis and to the Gibson-Cooke sweat test (GCST) as a control test. With sweat chloride concentrations of less than or equal to 40 mmol/L defined as normal and greater than 40 mmol/L as indicating persons at risk for CF, the new system showed 91% specificity and 100% sensitivity for CF, as compared with 92.8% and 100%, respectively, for the GCST. When we used sweat chloride concentrations of less than or equal to 60 mmol/L as probably normal and greater than 60 mmol/L as probably indicative of CF, the new system showed a 99.1% specificity and 98.6% sensitivity, vs 97.8% specificity and 97.9% sensitivity for the GCST test. In both procedures, occasionally insufficient sweat was collected, and this appeared related to the age of the subject. We conclude that the new sweat test system is potentially useful in physicians' offices, in clinics, and similar settings.

scholarly journals Cystic fibrosis with normal sweat chloride concentration: case report

2003 ◽  
Vol 58 (5) ◽  
pp. 260-262 ◽  
Author(s):  
Luiz Vicente Ferreira da Silva Filho ◽  
Maria Helena de Carvalho Ferreira Bussamra ◽  
Cleyde Miriam Aversa Nakaie ◽  
Fabíola Villac Adde ◽  
Joaquim Carlos Rodrigues ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Genetic Disease ◽  
Gold Standard ◽  
Diagnostic Tests ◽  
Chloride Concentration ◽  
Rapid Decrease ◽  
Compound Heterozygous ◽  
Sweat Chloride ◽  
Sweat Testing ◽  
Chloride Concentrations

Cystic fibrosis is a genetic disease usually diagnosed by abnormal sweat testing. We report a case of an 18-year-old female with bronchiectasis, chronic P. aeruginosa infection, and normal sweat chloride concentrations who experienced rapid decrease of lung function and clinical deterioration despite treatment. Given the high suspicion ofcystic fibrosis, broad genotyping testing was performed, showing a compound heterozygous with deltaF508 and 3849+10kb C->T mutations, therefore confirming cystic fibrosis diagnosis. Although the sweat chloride test remains the gold standard for the diagnosis of cystic fibrosis, alternative diagnostic tests such as genotyping and electrophysiologic measurements must be performed if there is suspicion of cystic fibrosis, despite normal or borderline sweat chloride levels.

Direct-measurement ion-selective electrodes: analytical error in hyponatremia.

1985 ◽  
Vol 31 (12) ◽  
pp. 2009-2012 ◽  
Author(s):  
D C Cowell ◽  
P M McGrady
Keyword(s):  
Direct Measurement ◽  
Reference Standards ◽  
Analytical Performance ◽  
Ion Selective Electrode ◽  
Ion Selective Electrodes ◽  
Selective Electrode ◽  
Laboratory Personnel ◽  
Analytical Error ◽  
Flame Emission ◽  
Sodium And Potassium

Abstract Using two commercial direct ion-selective-electrode sodium and potassium analyzers, we found lower sodium values in cases of hyponatremia as compared with those by flame emission spectrophotometry or indirect ion-selective-electrode analyzers. It is shown that these errors can be eliminated by modifying the calibrant, and that there is a requirement for internationally agreed-upon reference standards for use by manufacturers and laboratory personnel to assess analytical performance of these analyzers.

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