Organic analysis by ion chromatography. 1. Determination of aromatic amines and aromatic diisocyanates by cation-exchange chromatography with amperometric detection.
A method has been developed for the simultaneous determination of a range of aromatic amines using cation-exchange chromatography performed on a standard ion chromatography column using d.c. amperometric detection. The analytes separated were 2,4- and 2,6-toluenediamine (2,4- and 2,6-TDA), aniline, o-toluidine, benzidine, p-chloroaniline, 4,4'-diaminodiphenyl (4,4'-DDP), m-nitroaniline and 1-naphthylamine. A Dionex CS12 column was used with gradient elution from an initial eluent of 5% CH3CN+35 mM H2SO4 to 27% CH3CN+35 mM H2SO4 (at 35 min). Detection limits in the range 2.6-22.6 microg/l were observed for all analytes except m-nitroaniline, for which the detection limit was 201 microg/l. Linear calibrations and good precision were observed and the method was applied to the determination of benzidine, p-chloroaniline and 1-naphthylamine in wastewater samples. Further, the separation was also used (after some modification of the eluent conditions) for the determination of 2,4- and 2,6-toluene diisocyanate (2,4- and 2,6-TDI) and 4,4'-methylenediphenyl diisocyanate (4,4'-MDI) after their hydrolysis to 2,4-TDA, 2,6-TDA and 4,4'-DDP. Detection limits for 2,6- and 2,4-TDI and 4,4'-MDI were 3.8, 8.2, and 11.2 microg/l, respectively. The method was applied to the determination of diisocyanates in air.
Zhu
Yan
Y
Department of Chemistry, Zhejiang University, Hangzhou, China. zhu.yan@utas.edu.au
Wang
Muhua
M
Du
Huangyong
H
Wang
Fang
F
Mou
Shifen
S
Haddad
Paul R
PR
D000588:Amines / Q000032:analysis*; D002411:Cation Exchange Resins; D002852:Chromatography, Ion Exchange / Q000379:methods*; D004563:Electrochemistry / Q000379:methods*; D017953:Isocyanates / Q000032:analysis*; D012015:Reference Standards; D012680:Sensitivity and Specificity
D000588:Amines; D002411:Cation Exchange Resins; D017953:Isocyanates