Fully automated sequential injection analysis method for preconcentration of haloacetic acids in drinking water samples

摘要

The utilization of a specific preconcentration protocol within an automated, on-line drinking water analysis method to amplify detection levels of individual halo acetic acids is provided. The proposed sequential injection analysis procedures allow for measuring such levels in drinking water samples from remote locations with post-column reaction of ion chromatography (PCR-IC). The novel remote preconcentration method injects such known concentrations via a syringe at regular intervals in a manner to provide a baseline measurement that accords a reliable comparison with the unknown amounts present within the drinking water samples at issue. In such a manner, the on-line, remote system provides the necessary reliability for a water utility or like entity on which to base any further needed water treatment activities without having to perform such measurements in a distinct lab setting.

主权项

1. A fully automated method of analyzing drinking water samples in an on-line procedure and at a remote location along a drinking water supply line, said method including the identification and detection of concentration of haloacetic acid disinfection byproducts therein said drinking water sample, said method comprising:
a) providing at least one drinking water sample stream that has been disinfected with chlorinated or chloraminated disinfectants; b) providing a sequential injection analysis module, wherein said module includes a solid phase extraction component, a chemical reagent pump, and a valve to permit separate delivery of water and chemical reagents to said solid phase extraction component, wherein said reagents include a solid phase extraction component conditioning reagent, an acidic reagent, and a basic reagent, and a separate drinking water sample stream and acid delivery pump to deliver acidified drinking water samples to said solid phase extraction component; c) providing a separate PCR-IC instrument including at least one ion exchange column, and a fluorescence detector; d) conditioning said solid phase extraction component through introduction therein with said solid phase extraction component conditioning reagent; e) feeding said drinking water sample stream through said drinking water sample stream delivery pump into said solid phase extraction component with said acidic reagent from said chemical reagent pump and through said valve, thereby removing at least some of the haloacetic acids from said drinking water stream and forming an acidified preconcentrate formulation including at least one haloacetic acid bound to said solid phase extraction component, wherein said acidic reagent produces a pH in a range from about 0.8 to 2; f) feeding said basic reagent through said solid phase extraction component to elute said acidified preconcentrate formulation of step “e” from said solid phase extraction component; g) feeding the eluted preconcentrate formulation of step “f” through said PCR-IC instrument, including through said anion exchange column to provide separated haloacetic acid species streams; h) mixing said separated haloacetic species streams from step “g” with a dilute base and a fluorescing compound to form separate fluorescing haloacetic acid species streams therein; and i) transporting said separate fluorescing haloacetic acid species streams of step “h” to said fluorescence detector to determine the concentration of total haloacetic acids within all such fluorescing haloacetic acid species streams through fluorescence detection.