Determination of Fluoride in Fluoride Tablets and Solutions by Ion-Selective Electrode: Collaborative Study

1984 ◽  
Vol 67 (4) ◽  
pp. 682-684
Author(s):  
John R Marzilli ◽  
◽  
F L Acampora ◽  
L R Alexander ◽  
M Y Alpert ◽  
...  

Abstract A proposed method using the fluoride (F) ion-selective electrode has been developed for determining the fluoride ion concentration in tablets and solutions containing sodium fluoride. The method has been subjected to collaborative study. Eight samples consisting of 2 authentic fluoride solutions, 2 commercial fluoride solutions, and 4 commercial fluoride tablets were sent to each of 11 collaborators together with a copy of the method. Single assays on the authentic fluoride solutions known to contain 1 mg F/5 mL were performed with average recoveries of 99.5 and 99.6% and relative coefficients of variation (CV) of 2.11 and 1.91%, respectively. Single assays of 2 commercial fluoride solutions declared at 1 mg F/5 mL gave mean values of 0.994 and 0.990 mg and relative CV values of 1.88 and 2.36%, respectively. Single assays of 2 commercial fluoride tablet preparations declared at 0.5 mg F gave mean values of 0.485 and 0.478 mg and relative CV values of 3.12 and 3.71 %, respectively. Single assays of 2 commercial fluoride tablet preparations declared at 1 mg F gave mean values of 0.991 and 0.981 mg and relative CV values of 2.99 and 2.85%, respectively. The method has been adopted official first action.

Author(s):  
David C. Cowell

An automated method is described, using standard continuous flow techniques, for the determination of urine fluoride ion concentration using a fluoride ion selective electrode. It is shown that the kinetics of the electrode response to changes in fluoride ion can be used for the accurate measurement of fluoride ion concentration in urine, and that equilibration of the electrode response is not a prerequisite for the measurement of fluoride ion. Recovery experiments are in the range 83 to 90%; in-batch precision is between 0·9 and 1·6% and carryover 2·5% or less.


1987 ◽  
Vol 33 (2) ◽  
pp. 253-255 ◽  
Author(s):  
E Kissa

Abstract Inorganic fluoride in whole blood, serum, or plasma has been determined with a fluoride ion-selective electrode by adding the 0.5- to 2.0-mL sample to 20 mL of water containing a buffer and fluoride, 25 micrograms/L. The fluoride concentration in the sample is calculated from the resulting cell potential difference recorded after equilibrating for 10 min. This novel method has the advantages of simplicity, accuracy, and high precision, standard deviations for 5 to 7 replicate determinations of fluoride ranging from +/- 1.7 to +/- 2.4 micrograms/L. For whole blood from donors living in an area with fluorinated drinking water, the F- concentration was 20 to 60 micrograms/L.


1976 ◽  
Vol 59 (1) ◽  
pp. 53-55
Author(s):  
James E Graf ◽  
Troy E Vaughn ◽  
William H Kipp

Abstract The use of the bromide ion selective electrode for the determination of bromide ion in wine has been found to be rapid and reliable. The method has been used for still wines and carbonated wines and is applicable to all wines regardless of their country of origin. The method consists of treating a 50 ml aliquot of wine with 2 ml each of 3.75M H3PO4, saturated KNO3, and 1M CuSO4. After 10 min the electrodes are immersed in the samples and a millivolt reading is obtained. One hundred μl 500 ppm bromide ion standard is added and the millivolt reading is taken. Bromide ion concentration in the wine = (CΔ × 1)/((antilog ΔE/S) − 1) where CΔ = 1, ΔE = the change in potential expressed in millivolts, and S = the electrode slope.


1981 ◽  
Vol 64 (4) ◽  
pp. 808-813
Author(s):  
Wallace S Brammell ◽  
◽  
C Arozarena ◽  
J Hunter ◽  
H G Kiernan ◽  
...  

Abstract A simple and rapid spectrophotometric method was developed for determining the total phosphorus content of certifiable straight color additives. The dye sample is mixed with a cellulose powder and MgO mixture, and ashed at 500°C in a small Pyrex beaker in a muffle furnace. The ash is dissolved in vanadomolybdic acid reagent and filtered through glass wool, and the absorbance of the resulting yellow molybdovanadophosphoric acid solution is measured at 400 nm. The total phosphorus content of the sample, expressed as percent Na3PO4, is determined from a standard curve. Recovery of phosphorus added as KH2PO4 to 39 different dyes in amounts equivalent to 0.300% Na3PO4 ranged from 95.3 to 106.8%, averaging 100.6%. In the collaborative study, 7 laboratories successfully performed duplicate analyses of 6 different dyes (D&C Orange No. 5, D&C Yellow No. 8, FD&C Blue No. 2, FD&C Red No. 3, FD&C Red No. 40, and FD&C Green No. 3). The mean values found ranged from 0.325 to 6.86% Na3PO4. In general, the accuracy and reproducibility of the method were satisfactory, with single determination coefficients of variation ranging from 3.76 to 9.60%. The method was adopted official first action.


2000 ◽  
Vol 83 (4) ◽  
pp. 933-943 ◽  
Author(s):  
P Christopher Ellis ◽  
Lori F Pivarnik ◽  
Mamadou Thiam ◽  
L Berger ◽  
S Field ◽  
...  

Abstract Nine collaborating laboratories tested a combination of 23 seafood samples for volatile bases using an ammonia ion selective electrode. Results were reported as mg NH3/100 g fish, but the method reflected levels of both ammonia and trimethylamine, which permeated the ammonia membrane. The 23 samples were broken down into 8 blind duplicate pairs, 2 Youden matched pairs, and 3 single samples covering fresh to spoiled product ranging from 8 to 82 mg NH3/100 g. Seven species were evaluated: Atlantic cod, squid, Atlantic halibut, gray sole, monkfish, dogfish, and Atlantic mackerel. The ammonia electrode assay was performed on an aqueous homogenate consisting of 95 mL distilled water and 5.0 g sample tissue. Alkaline ion strength adjusting solution (2 mL) was added to the homogenate to liberate ammonia that was sensed by the ion specific electrode and measured on a precalibrated portable meter. Repeatability standard deviations (RSDr) ranged from 4.2 to 17%; reproducibility standard deviations (RSDR) ranged from 8.8 to 21%. A standard ammonium chloride solution was provided to all laboratories to spike 3 different samples at 10 mg NH3/100 g. Recoveries of added ammonia as ammonium chloride for fresh, borderline, and spoiled samples were 88.6, 107, and 128%, respectively.


1986 ◽  
Vol 69 (2) ◽  
pp. 196-198 ◽  
Author(s):  
Michael P Carlson ◽  
Norman R Schneider ◽  
◽  
R Everson ◽  
J Johnson ◽  
...  

Abstract Each of 10 collaborating laboratories analyzed 4 blind duplicate pairs of forage samples for nitrate, by using a potentiometric method. Two forage controls and a 100 000 mg KNO3/L standard were also provided. Nitrate was extracted into an aqueous Al2(SO4)3 solution containing 70 mg KNO3/L and quantitated with a nitrate-selective electrode. Standards were prepared using extracting solution as diluent. Nitrate concentrations in forage samples ranged from <0.50 to 4.35% KNO3. Repeatability coefficients of variation (CV0) ranged from 1.74 to 3.61%, and reproducibility coefficients of variation (CV1) ranged from 6.92 to 7.66%. Mean recovery of a 0.55% KNO3 spike was 94.5%. The method has been adopted official first action.


2007 ◽  
Vol 95 (10) ◽  
Author(s):  
R. M. Sawant ◽  
M. A. Mahajan ◽  
Poonam Verma ◽  
Dipti Shah ◽  
U. K. Thakur ◽  
...  

The determination of fluoride from diverse matrices at front and back end of nuclear technology and some studies from this laboratory on optimizations of different experimental parameters differing with multiple fuels and reactor materials, have been reviewed. The most useful techniques such as fluoride ion selective electrode (F-ISE) and ion-chromatography (IC) widely adopted as routine methods for fluoride determination in nuclear industry have been discussed. The effect of various buffer strengths on the response of the fluoride ion selective electrode has been examined. The ion chromatographic studies on mobile phase concentration, medium of sample, sample injection volume


Sign in / Sign up

Export Citation Format

Share Document