An automated, continuous-flow system is utilized to determine specific conductance and pH simultaneously in natural waters. A direct electrometric procedure is used to determine values in the range pH 4–9. The specific conductance measurements are made with an electronically modified, commercially available conductivity meter interfaced to a separate module containing the readout control devices and printer. The system is designed to switch ranges automatically to accommodate optimum analysis of widely varying conductances ranging from a few μmhos cm-1 to 15,000 μmho cm-1. Thirty samples per hour can be analyzed. Comparison of manual and automated procedures for 40 samples showed that the average differences were 1.3% for specific conductance and 0.07 units for pH. The relative standard deviation for 25 replicate values for each of five samples was significantly less than 1% for the specific conductance determination; the standard deviation for the pH determination was ⩽ 0.06 pH units.
|Title||An automated procedure for the simultaneous determination of specific conductance and pH in natural water samples|
|Authors||D. E. Eradmann, Howard E. Taylor|
|Publication Subtype||Journal Article|
|Series Title||Analytica Chimica Acta|
|Record Source||USGS Publications Warehouse|
|USGS Organization||National Research Program - Central Branch|