Presentation on theme: "Determination of pH, Ca2+ and Mg2+ in Saliva"— Presentation transcript:
1 Determination of pH, Ca2+ and Mg2+ in Saliva Cody ChalkerDavid JuliaReal World Project Fall 2009
2 Electrolytes in Saliva Na+ K+,Ca2+ Mg2+(mM): Cu2+ Pb2+ (µM),Electrolyte Conc. affected by flow rate and diseaseOnly bound and free Ca2+ can be measured simultaneously10% bound to proteins, 40% to phosphates, citrates and lactates, 5% to bicarbonate; Thus approx. 45% is in ionic form
3 Bicarbonate and pH Bicarbonate a product of cell metabolism Bicarbonate does not buffer it mainly neutralizesBicarbonate concentration in saliva is linked to flow rate
4 Reasons for testing pH of saliva The ability to monitor health status, disease onset and progression, and treatment outcome through noninvasive means is a highly desirable goal in health care promotion and delivery.Oral fluid is a perfect medium to be explored for health and disease surveillance.
5 Importance A healthy individual should have a saliva pH of 6.5-7.4 Most ailments such as cancer, kidney stones, heart disease, etc. are associated with an acidic pH in the bodyAs you age the pH of your saliva changesOver half of adults are acidic at 6.5, symbolizes signs of aging i.e. calcium deficiency.Most children are around a pH of 7.5Most cancer patients have a pH of 4.5 while in terminal condition.
6 Why Hasn’t This Been Studied Before? One of the main reasons this is just becoming a research topic is that the amount of ions in saliva are so small that not until recently were techniques used to be able to make affirmative quantitative assumptions
7 Techniques Used TodayMicrofluidics and Microelectromechanical systems are MEMS used for salivary diagnosticsMEMS are integrated systems composed of mechanical elements, sensors, actuators and electronics on a common silicon substrate developed through micro fabrication technology
8 Other Techniques Used Today Electrochemical methods have been devisedThiocynate is an example of an ion being studiedProcess includes high performance liquid chromatography, silica gels, and ion specific electrodesPros of procedure: that it is quick, precise, and requires few samples
9 Techniques Used pH of saliva: Saliva was taken from volunteer who were asked to build up approx. 1-2mL of saliva which was then extracted with a disposable pipette. The saliva was then immediately immersed in paraffin oilCO2 + H2O H2CO HCO3- + H+
10 pH cont’dTo finish testing the pH of saliva 8mL of water was added to each sample. The water added was boiled for an hour and found to have a pH of 6.75pH glass-electrode probe was calibrated with different pH buffers to obtain pH values 4,7, and 10Following the calibration the pH probe was immersed into each sample
11 Determination of Magnesium and Calcium Determination of the two ions cannot be found exclusively through an EDTA titration since both Magnesium and Calcium complex to EDTAVolunteers were asked to collect as much spit in their mouths(approx. 5mL), sans mucus, and spit only once into the beaker8mL of buffer-indicator was added. Standard was made of 8mL of water and 1mL of indicator.Standard was titrated with EDTA solution to determine approximate end point. Each sample was titrated to an end point
12 Determination of Magnesium Thiazole yellow was used as an indicatorAmmonium Oxalate was used to precipitate out calciumUV Vis instrument
13 Procedure for Use in UV Vis Saliva samples were mixed with ammonium oxalate and centrifuged (suspected problem area)0.75mL of each sample was added to cuvettes. 0.75mL additions were added of water, polyvinyl alcohol, thiazole yellow and of NaOHThe UV Vis was calibrated with magnesium concentrations of .1mM, .2mM, and .3mM. Each sample was run against these concentrations
14 ResultsUsing a glass-electrode the pH of 5 samples were found to be 7.25, 7.4, 7.45, 7.3, 7.3.EDTA titration of saliva involves small amounts of either ion concentration. To determine the concentration of the two ions a comparison is made against a standardSamplemM Mg/L.05% EDTA mL added10.110.2420.130.2930.230.3540.340.4150.540.6160.830.95
18 Magnesium ResultsThe results for magnesium concentration were obtained via UV Vis.The experimental results proved to be elusive. Quantitative data was unable to be obtained.
19 Conclusion The results show: An equation that describes the Mg concentration in saliva at low concentrationsCan effectively determine pH of Saliva with a glass electrode pH meterWhat techniques are used today to determine pH, [Mg2+], and [Ca2+].Real world application and importance.
20 ReferencesStarr, Henry. "Studies of Human Mixed Saliva". The Journal of Biological Chemistry. Philadelphia: Robert Hare Laboratory school of medicine, 1922.Wong, David. "Salivary diagnostics powered by". American Dental Association 2006:Ericsson, Yngve. "Simplified Methods for Determination of Calcium and Magnesium in the Saliva". Journal of Dental Research 1955: