Abstract: To prevent nutrient enrichment and, hence undesirable ecological impacts, nutrients monitored in wastewater samples include two anionic species, i.e., NO3-and PO43-, and a cationic species, NH4+. Ion chromatography (IC) is a popularly used technique to determination NO3-and PO43-in these samples, whereas NH4+ determination in wastewater is typically done using manual or automated wet chemistry, e.g., flow injection analysis (FIA). A sequential IC-FIA method was developed, using Lachat's QC8000 IC system, which determines NO3-, PO43-, and NH4+ in a single injection. In this system, a QuikChem Small Suppressor cartridge is regenerated between samples. A sample is injected while leaving the suppressor off-line. NH4+, a cation, elutes in the void volume of an anion exchange column. The unsuppressed column effluent, exiting the conductivity flow cell, up to this point is used for FIA determination of NH3. When NH3 exits the conductivity flow cell, a fully regenerated suppressor is brought inline for conductometric detection of anions. Analog data are simultaneously acquired from colorimetric and conductometric detectors, for cationic and anionic nutrients, respectively. This method is accurate with spike recoveries in wastewater samples of 91% for NO3-to 114% for Cl-. It is precise with relative standard deviation values, for replicate analyzes (n=7) of a mid-range standard ranging from 0.4% for PO43-to 1% for NO3-.

Abstract: Nitrite and F-, Cl-, NO3- Br-, HPO42-, SO42- were determined in wastewater, , groundwater and surface water samples by enhanced ion chromatography with sequential flow injection anal.