Synthesis of a Potential New Internal Standard for the Analytical Determination of Dibutyl Phthalate (DBP) and Monobutyl Phthalate (MBP) in Water Samples

Abstract

Dibutyl phthalate (DPB), a common plasticizer, and monobutyl phthalate (MBP), a DBPmetabolite, are endocrine disruptors that leach into water sources through various pathways.Someof the most useful methods to find and quantify the concentrations of these pollutants in drinkingwater include using gas chromatography-mass spectrophotometry (GC-MS) with solid phase microextraction (SPME), with the application of benzyl benzoate (BB) as an internal standard. However,since BB is also a common water pollutant and could interfere with practical analytical measurements,there is a need for a new internal standard. A new compound, dibutyl 4-chlorophthalate (Cl-DBP), isproposed as a potentially improved internal standard, because it shares characteristics with DBP andMBP, including the high ionizability of both the compounds as well as a common mass spectrometryfragmentation pattern. The synthesis, purification, and analysis of Cl-DBP as a potential internalstandard for the quantitation of butyl derived phthalate plasticizers by GC-MS will be presented.