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Methods are described for determining pentachlorophenol (PCP), hexachlorodibenzo-p-dioxin (HCDD), octachlorodibenzo-p-dioxin (OCDD) in bovine milk. The PCP method consists of sulfuric acid digestion, silica gel column chromatography, methylation, alumina column chromatography, and detection with electron capture-gas chromatography (EC-GC). The chlorodioxin procedure consists of extraction from basic solution, acid wash, silica gel and alumina column chromatography, and detection by EC-GC and/or gas chromatography-mass spectrometry (GC-MS). Recoveries for PCP, HCDD, and OCDD were 80, 80, and 100%, respectively. Samples of some quarantined milk from the State of Michigan gave no detectable signal for PCP, HCDD, and OCDD at the detection limits of 10-15, 0.025, and 0.05 ppb, respectively.

All aspects of the use of mass spectrometry for the identification and quantitation of chlorodibenzo-p-dioxins are critically reviewed. The mass spectra obtained by various ionization methods are discussed. Numerous mass spectral techniques and cleanup procedures are covered, with emphasis on their interrelationships. These techniques have been applied to the determination of chlorodibenzo-p-dioxins in many different matrices, including product materials, such as chlorophenols and phenoxy acid herbicides, and toxicological and environmental materials such as cattle, fish, rodent and human tissues. Formation and degradation studies, which include thermal chemistry, photochemistry and chemical stability and degradation, are presented. Numerous considerations in the handling and quantitation of chlorodibenzo-p-dioxins, such as interferences, detection limits and recovery studies, are evaluated.