Abstract
The use of a small guard column (5-mm length) as a miniature analytical column in low-pressure liquid chromatography based on a sequential injection with lab-on-valve system was demonstrated. A strong initial mobile phase was used to rapidly deliver the sample zone to the column prior to simultaneous separation of analytes with weaker mobile phase. Separation of methyl-, ethyl-, propyl-, and butyl-4-hydroxybenzoates (MP, EP, PP, and BP) was achieved within about 120 s with sufficient peak resolution (all higher than 1.3) using 2,500 µL of mobile phase (composed of 1,087 µL of MeOH) per run. Detection limits were found to be 6.5, 8.0, 0.5, and 0.6 μmol L−1 for MP, EP, PP, and BP, respectively. The system was tested with common commercially available skin lotions and wet wipe products. The analysis results were in good agreement with those obtained from the high-performance liquid chromatography with a 10-cm-length packed column.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
