IPT08
QUALITY CONTROL TESTS ON MOUTHWASH
Last Revised: May 2015 1. PURPOSE This exercise performs a number of quality checks on a sample of mouthwash. 2. REAGENTS & EQUIPMENT 2.1 Fluoride ISE 2.2 Gas chromatograph set up to separate alkanols 2.3 Refractometer 2.4 UV‐VIS scanning spectrophotometer 2.5 Fluoride standards, 50 & 100 mg/L 2.6 TISAB (in auto dispenser) 2.7 Plastic 100 mL volumetric flasks 2.8 Ethanol in water standard ‐ 20%v/v 3. PROCEDURE 3A. Visible absorption spectrum 3.1 Record the spectrum of the undiluted sample (using a water blank) in plastic cells from 400‐
700 nm. 3.2 Record the absorbance of the peaks at 414 and 626 nm. 3B. Refractive index 3.3 Measure the RI of water. 3.4 Measure the RI of the undiluted sample. 3C. Fluoride content 3.5 Pipette 5 mL of sample into a clean plastic cup, and add 20 mL of water by measuring cylinder and 25 mL of TISAB. 3.6 Repeat step 3.5 with 5 mL of the 50 and 100 mg/L standards. 3.7 Measure the response of each solution with the fluoride ISE. 3D. Ethanol content 3.8 Inject, in duplicate, 1 uL of the undiluted sample and the standard. 3.9 Measure the peak height of the ethanol peak in each chromatogram. 3E. pH 3.10 Calibrate the pH meter with pH7 & 4 standards. Record the values for each after adjustment. 3.11 Record the pH of the undiluted sample/ Refractive Index RIadj  RImeas  (RIwater  1.333 ) Ethanol Content %EtOH 
20 x PA samp
PA std
ISE Sensitivity & Fluoride Content (mg/L) Use spreadsheet provided on website. REPORTING 
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IPT08 calculate the necessary values for recording on the Analysis Certificate ensure all PASS/FAIL results are recorded p2 DAFFY’S ANALYTICAL SERVICES
ANALYSIS CERTIFICATE
Product tested Listerine Teeth Defence Sample identification Bottle size Expiry Date Other codes Date Analyst name Analyst signature Analytical results Parameter Refractive Index * Specification Range
Measured Value
Pass/Fail 1.360‐1.370 PASS/FAIL Sample pH # 4.1‐4.3 PASS/FAIL pH 4 Std pH # 3.9‐4.1 PASS/FAIL Abs. @ 414 nm # 0.42‐0.48 PASS/FAIL Abs. @ 626 nm # 0.29‐0.35 PASS/FAIL % Ethanol * 21‐23 PASS/FAIL Fluoride mg/L * 90‐110 PASS/FAIL ISE sensitivity * 50‐65 PASS/FAIL # direct reading from instrument * result from calculation Teacher use only Log on Log off Reagent sheet Risk assessment IPT08 p2