title: Analysis of p-chlorobenzoic acid in water by liquid chromatography-tandem mass spectrometry.
abstract: para-Chlorobenzoic acid (p-CBA) is typically used as a probe compound to indirectly quantify hydroxyl radicals formed during advanced oxidation processes used in drinking water and wastewater treatment. A method has been developed for the sensitive analysis of p-CBA in water using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A reporting limit in water of 100 ng/L was determined for the method, which is 40-fold lower than the 4.0 microg/L reporting limit of the widely used liquid chromatography with UV detection (LC-UV) method. The method was found to be robust in difficult matrices such as wastewater and highly selective, unlike LC-UV which relies on non-specific detection at 234 nm. The detection of p-CBA below 1 microg/L during bench-scale ozonation of wastewater after hydrogen peroxide addition was demonstrated. Duplicate samples were analyzed by LC-MS/MS and LC-UV and results were found to be comparable at concentrations quantifiable by both methods.
authors: Southern Nevada Water Authority, Henderson, NV 89015, USA. brett.vanderford@snwa.com
authors: Brett J
authors: BJ
authors: Vanderford
authors: Fernando L
authors: FL
authors: Rosario-Ortiz
authors: Shane A
authors: SA
authors: Snyder
mesh_terms: D002723:Chlorobenzoates / Q000032:analysis* / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry; D015394:Molecular Structure; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014867:Water / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply / Q000032:analysis
chemical_list: D002723:Chlorobenzoates; D014874:Water Pollutants, Chemical; D014867:Water; D006861:Hydrogen Peroxide