Calculated sensitivity of the developed method for fluoride determination was 1 × 10 −3 mg/L of fluoride. C ð %; m: m Þ¼ C 1. [1] I’ve used the rough estimate available from a few different sources online that there are about 90,000 drops of water in a gallon. 100 E þ C 2. Determination of fluoride in toothpaste with an fluoride selective electrode My student no: 100203583 An ion selective electrode is an electrode that is able to detect and give a response for certain ions. I’m also assuming you have pure fluoride in liquid form (which is a bit of a stretch, but use your imagination!) Total fluoride concentrations in the toothpaste. were obtained by means of the following formula . In this experiment, the fluoride content of (1) an unknown NaF solution, and (2) toothpaste will be measured by direct current potentiometry with a fluoride ion activity electrode in a high ionic strength medium. Prescription strength toothpaste contains sodium fluoride at a concentration of over 1500ppm up to 5,000ppm. But all toothpastes, even prescription ones, will contain other ingredients that target oral health problems such as bad breath, tartar build up and sensitivity. The defined procedures for sample preparation were shown to be reliable, which was indicated by good recovery of the spiked non-fluoride samples (96–98%) as well as analyzed fluoride-containing samples (94–103%). For example, solutions containing 1:1 electrolyte, like NaCl, µ = [NaCl]. Very small concentrations of fluoride-ions (to 10–6 mol/dm3) can be determined by fluoride selective electrode, with regulation of ion strength of a solution and control of concentration of hydroxide ions and interfering ions of metals. Fluoride is an important aspect of dental care and has been widely used for several years. fluoride levels ranging between 1.2 to 1.4 ppm.2 Fluoride compounds are found in food and drinks that are consumed daily, however, the concentration of fluoride found in these items varies. i = concentration of the i th ion, z i is the charge of the i th ion. In this study, the fluoride concentration of thirteen toothpaste samples (paediatric and adult) in Nigeria purchased from open markets and supermarkets were determined potentiometrically using a fluoride ion- selective electrode. I decided to use one ppm of fluoride since that is the average fluoride concentration in most fluoridated water.