a method is presented , wherein concentrated dichloromethane extracts from malt , beer , and nonfat dried milk powder containing n-nitrosodimethylamine ( ndma ) , and fried dry-cured and pump-cured bacon containing ndma and n-nitrosopyrrolidine ( npyr ) undergo 3n hclo4-celite microcolumn cleanup followed by peroxidation with pentafluoroperoxybenzoic acid , a stable solid peroxyacid , to n-nitrodimethylamine and n-nitropyrrolidine , as an aid to nitrosamine confirmation .
C0027253
n-nitrosopyrrolidine
C0028197
nitrosamine