Table 3. Reported Molar Ratios of Pre-screened DES Combinations in the Literature.

#	HBA	HBD 1	molar ratios	ref
DES#01	betaine	ethanolamine		N.R.
DES#02	betaine	oxalic acid	2:1	(17,119,120)
DES#03	betaine	citric acid	1:1	(13,17,121−123)
DES#04	betaine	gallic acid		N.R.
DES#05	betaine	triethylene glycol	1:4	(124,125)
DES#06	choline chloride	ethanolamine	1:6	(60,126,127)
DES#07	choline chloride	oxalic acid	1:1	(17,128,129)
DES#08	choline chloride	citric acid	2:1	(17,130−132)
DES#09	choline chloride	gallic acid	2:1	(110)
DES#10	choline chloride	triethylene glycol	1:3	(133)