QUANTITATIVE-ANALYSIS OF A BIOCIDE IN SILICONE EMULSIONS USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

`Traditional high performance liquid chromatographic (HPLC) methods ar e not typically used for characterization of silicones, due to a lack of absorption in the ultraviolet (UV) region of the spectrum. However, many additives in water-based, silicone formulations absorb in the UV and can be quantified using an HPLC method. Direct injection of a sil icone emulsion can lead to irreversible deposition of siloxane polymer on an HPLC column and should be avoided. This paper describes a sampl e preparation procedure in which the silicone emulsion is ''broken'' a nd the polymer precipitated prior to chromatographic analysis of the a queous phase. A reverse-phase, HPLC method, originally developed by Ro hm and Haas, was modified and used to quantify the two active componen ts of Kathon(R) CG Biocide in Dow Coming(R) 1784 Emulsion using this s ample preparation procedure. This procedure was also shown to be effec tive for quantitation of Kathon(R) LX in Dow Corning(R) Antifoam B and may be applicable to analysis of Kathon(R) in a wide variety of silic one emulsions.