Acidic sample (Hydrobenzoic acids)

Sample: 10 µl, 10 ppm each

1. p-Hyroxybenzonate methyl

2. p-Hyroxybenzoic acid ethyl

3. p-Hyroxybenzoic acid propyl

4. p-Hyroxybenzoic acid butyl

 Eluent: ACN/H2O=50/50
 Flow rate: 1.0 mL/min
 Column temp.: 30 °C
 Detector: UV (254 nm)