Table 1.

Standards used for the determination of phenolic acids.

Standard	λmax	Equation linearity	R2
Caffeic acid	280	13.887x-6.0066	1
Chlorogenic acid	280	2.9963x+1.1789	0.9998
Gallic acid	280	22.279x-2.1165	0.9998
p-hydroxybenzoic acid	280	26.879x+6.102	0.9985
p-coumaric acid	280	53.748x-17.437	0.9994
Syringic acid	280	46.283x+2.674	1
Ferulic acid	280	14.481–5.4053	1