This paper describes a method for on-line addition of stannous chloride for determination of mercury by ICP-OES. This method allows mercury detection from µg/L to μg/L.
This document details a method for determining mercury (Hg) in various water types and wastes using an Agilent 720-ES axially-viewing Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES). The method employs on-line addition of stannous chloride (SnCl2) as a reducing agent to enhance the Hg signal, allowing for detection in the pg/L range without requiring a dedicated cold vapor generation accessory like the VGA-77.
The text outlines the instrumentation setup, including the use of a four-channel peristaltic pump and a Y-piece to combine sample and reductant flows. It provides specific operating parameters, sample preparation instructions for NIST 1641D reference material, and discusses the results of signal enhancement and detection limits achieved with this technique.
| Power | 1.2 kW |
|---|---|
| Plasma gas flow | 15 L/min |
| Auxiliary gas flow | 1.5 L/min |
| Nebulizer flow | 0.65 L/min |
| Pump speed | 12 rpm |
| Sample uptake rate | 1.0 mL/min |
| Replicate read time | 30s |
| Sample uptake delay time | 80s |
| Rinse time | 120s |
Soak the torch in concentrated HCl to dissolve the white SnO2 deposit, then rinse with de-ionized water and dry.
To remove the deposit, soak the torch directly in concentrated HCl to dissolve it, then rinse with de-ionized water and allow it to dry.