the method is based on exchange of active hydrogen for deuterium occurring during the chemical ionization process using trideuterioammonia , with comparison of m/z for ammonium adduct [ m + nh1 ] + and trideuterioammonium adduct [ m -- nh + nd + nd4 ] + , or of protonated molecular ion [ m + h ] + and deuteronated molecular ion [ m -- nh + nd + d ] + yielding the number of active hydrogens .
C0011744
deuterium
C0020275
hydrogens