Table 5 Purification condition and crystallization for 5-ALA salts

Dowex 50Wx8

Sodium acetate (1 M)

90 ± 4

Venosa et al. (2004)

Amberlite IR-120B

Ammonia (0.3 M)

100

Okada et al.  (2016)

Dowex 50Wx8

Sodium acetate (1 M, pH 4.67) followed by sodium acetate (1 M, pH 3.8)

70

Tripetch et al. (2013)

ALA-HCl

Add HCl with 2 times of 5-ALA volume and concentrate the solution to 3 M. Then add aqueous ALA-HCl dropwise to the poor solvents and precipitated crystals of ALA-HCl would be recovered on a filter paper

ND

99.5

Okada et al. (2016)

ALA-Phosphate

Adjust 0.1 M 5-ALA to pH 2.8 ~ 3.2 by adding phosphoric acid. Condense the ALA-phosphate solution to 400–600 g/L before cooling crystallization with 10 ~ 15 °C/h cooling rate and stirring speed 50–200 rpm

91

99

Lin et al. (2014)