National Institute for Occupational Safety and Health, NIOSH Manual of Analytical Methods… (1994)
“ Inject sample aliquot manually using solvent flush technique or with autosampler. NOTE 1: Under these conditions, approximate retention times are 4 min for dibutyl phosphate and 6 min for tributyl phosphate. NOTE 2: If peak area is above the linear range of the working standards, dilute with eluent, reanalyze, and apply the appropriate dilution factor in calculations. Measure peak area. Divide the peak area of dibutyl phosphate derivative by the peak area of internal standard on the same chromatogram. ”
