Analyte: Dalapon methyl ester, CAS Number: 17640-02-7; Analyte: Methyl dibromoacetate, CAS Number: 6482-26-4; Analyte: Methyl chloroacetate, CAS Number: 96-34-4; Analyte: Methyl dichloroacetate, CAS Number: 116-54-1; Analyte: Methyl trichloroacetate, CAS Number: 598-99-2; Analyte: Methyl bromoacetate, CAS Number: 96-32-2; Analyte: Methyl bromochloroacetate, CAS Number: 20428-74-4 ; . EPA, Method: 552.1.