Tryptic digest of insulin gives a number of disulfide containing peptides, which in the negative ion mode may cleave around the disulfide link to give fragment anions which may then be sequenced to provide the structure of the original tryptic fragment.
Phys. Chem. Chem. Phys., 2010, 12, 13555-13565
High level ab initio quantum chemical calculations have been performed on the association of chloroform with ammonia in the gas phase and compared to direct absorption infrared spectra at very low temperatures.