Table 2.

Representative derivatization reactions for biomolecules by ambient MS

Functional Groups	Reagents	Target compounds	Ambient MS method
Aldehydes and ketones	Girard’s reagent T, hydroxylamine, dinitrophenylhydrazine	Cortisone in oral fluid, steroid hormones [Huang et al. (72)], malondialdehyde in tissue [Girod et al. (77)]	PS, DESI
Alcohols	Betaine aldehyde	Cholesterol in tissue [Wu et al. (45)]	DESI
	Phenylboronic acid	Saccharides in urine [Gómez-Ríosa et al. (37)]	DESI
Amines	Bis(sulfosuccinimidyl) suberate, acetone	Cross-linking of peptides containing asparagine, glutamine, arginine, or lysine, amino acids [Gómez-Ríosa et al. (37)]	DESI
Disulfides and thiols	Dithiothreitol	Oxidized glutathione and insulin [Peng et al. (43)]	ELDI
Alkenes	Ozone, silver nitrate	Unsaturated lipids in bacteria, algae and animal preimplantation embryos [González-Serrano et al. (40), Zhang et al. (41), Jackson et al. (42)]	LTP, PS, DESI