Quantitative determination of Chromium: A comparison of three instruments
S Walley, P R S Cobham, P Vinden
A comparison is made between three instruments for measuring levels of chromium in the leachate of copper-chrome-arsenic (CCA) treated timber. These include an atomic absorption spectrophotometer, an inductively coupled plasma spectrometer and the RQflexâ. The RQflexâ is a new hand-held instrument which measures chromium by dipping a ReflectoquantÒ strip into the leachate and inserting the strip into the RQflexâ. Readings are determined reflectometrically following a reaction between chrome and the Reflectoquantâ strip. It provides an inexpensive and quick technique which is used in this paper to determine the degree of preservative fixation prior to the removal of CCA treated timber from drip pads of wood treatment sites. The results indicate that RQflexâ is a suitable instrument for the rapid assessment of chromium levels in rain wash off from treated timber. A comparison is given of the economics and accuracy of the instruments for measuring chromium.