Comparison of Three Different Liquid Chromatography-Mass Spectrometry Interfacing Techniques for the Determination of Priority Phenolic Compounds in Water

✍ Scribed by Puig, D.; Barcelo, D.; Silgoner, I.; Grasserbauer, M.

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 966 KB
• Volume: 31
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(199611)31:11<1297::aid-jms425>3.0.co;2-l

✦ Synopsis

A comparative study of the performance of three liquid chromatography-mass spectrometry (LC-MS) interfacing techniques, thermospray (TSP), atmospheric pressure chemical ionization (APCI) and ionspray (ISP) for the analysis of priority phenolic compounds was carried out, using the negative ion mode (NI). When using the TSP interface, IM -HIor [M + CH,COO] -were obtained as the main ions. APCI and ISP interfaces gave [ M -H j -as the main ion with an optimal extraction voltage in the range of 20-30 V. Phenol, 4-methylphenol and 2,4-dimethylphenol could only be monitored with ISP by raising the organic modifier percentage to 100%. Hence a porous graphitic carbon (PGC) analytical column was used instead to elute the analytes in a suitable retention window. Calibration graphs were linear from 1 to 100 ng for each compound with repeatability values of 15-20%. Instrumental detection limits (IDLs) obtained with ISP were in the range of those of TSP. An improvement of one order of magnitude could be achieved when working with APCL, which gave IDLs ranging from 3 to 180 ng in full scan and from 0.001 to 0.085 ng in single ion monitoring (SIM) mode. Furthermore, in APCI abundant structural information was obtained via fragmentation by raising the cone voltage from 20 to 60 V.

Application to the analysis of water samples after preconcentration using sulfonated styrene divinylbenzene (SDB-RPS) Empore disks is also reported. The entire analytical protocol was validated by analyzing samples at low pg/l levels distributed by the Aquacheck interlaboratory program (WRC, Medmenham, UK).