121 DI-n-BUTYL PHTHALATE 7. ANALYTICAL METHODS

The purpose of this chapter is to describe the analytical methods that are available for detecting, measuring, and/or monitoring di-n-butyl phthalate, its metabolites, and other biomarkers of exposure and effect to di-n-butyl phthalate. The intent is not to provide an exhaustive list of analytical methods. Rather, the intention is to identify well-established methods that are used as the standard methods of analysis. Many of the analytical methods used for environmental samples are the methods approved by federal agencies and organizations such as EPA and the National Institute for Occupational Safety and Health (NIOSH). Other methods presented in this chapter are those that are approved by groups such as the Association of Official Analytical Chemists (AOAC) and the American Public Health Association (APHA). Additionally, analytical methods are included that modify previously used methods to obtain lower detection limits and/or to improve accuracy and precision. Di-n-butyl phthalate may be determined by high resolution gas chromatography with an electron capture detector (HRGC/ECD) (EPA 1984b), gas chromatography/mass spectrometry (GC/MS) (EPA 1994a), gas chromatography with a flame ionization detector (GC/FID) (NIOSH 1994), gas chromatography/Fourier transform infrared spectrometry (GC/FTIR) (EPA 1994b), high performance liquid chromatography/mass spectrometry (HPLC/MS) (Coldham et al. 1998), or high performance liquid chromatography/ion-tra