Date of Defense




First Advisor

Adrian Vanderwielen, Chemistry

Second Advisor

Kevin Jenkins, The Upjohn Company

Third Advisor

Donald Schreiber, Chemistry


The cleaning validation unit at the Upjohn Company has been investigating methods for testing production equipment for residual cleaning agents. Five different methods (using three instruments) have been evaluated. Sodium, potassium, phosphates and/or carbon are the main ingredients found in most cleaning agents. Ion Chromatography was used to test for sodium, phosphates, and potassium. A UV spectrophotometricmethod was used to test for phosphates. Total organic carbon was used to test for carbon. All of the methods were found to be linear over ranges ofinterest. In order to ensure that any residual cleaning agent can be detected by the method the analytical limit should not exceed the amount of the substance found in the final rinse water used in production's cleaning processes. The analytical limit for a method is taken to be either the lowest value that can be detected by the instrument or the background value of the water used in sample preparation. The analytical limits for each of the methods are as follows: ion chromatography for sodium - 57.2 ppb, ion chromatography for potassium - 9.45 ppb, ion chromatography for phosphates - 200 ppb, UV method for phosphates - 10 ppb, and total organic carbon method - 303 ppb. The production water was found to contain 394 ppb sodium, 125 ppb potassium, 19.2 ppb phosphate and 1.93 ppm carbon. The only method that does not have a limit lower than the background concentration of the purified water is the ion chromatography method for determination of phosphate. The UV method can be used to measure the phosphate concentration of the samples; however, it is a very time consuming assay. The final limit for the UV method may actually be higher than the limit for ion chromatography because the sample size (100 mL) is about 20 times the ion chromatography sample size (about 6 mL). Ion chromatography can also be used to test for ammonium and chlorides. It is recommended that these methods be investigated before implementing assays with cleaning agent residue limits of greater than 50 ppm.

Access Setting

Honors Thesis-Campus Only