Wood Preservatives Analysis by XRF Spectrometry

Wood Preservative Test ApplicationThe following is the introduction to Oxford Instruments' application brief on the use of x-ray fluorescence spectrometry for the analysis of wood preservatives (Pentachlorophenol, Chromated Copper Arsenate, Copper-only compounds) and treated lumber.

Wood Preservatives AnalysisAmong many other building materials, wood is idea as it is strong, easily shaped, and renewable.  Its biggest inconvenience is that it is vulnerable to decay and insects.  To make it more druable, wood is usually pressure-treated with wood preservative solutions that have insecticide, fungicide, and herbicide properties.  The two most widely used wood preservatives are Chromated Copper Arsenate (CCA) and Pentachlorophenol (Penta).  Due to their lower risk to health, copper-only solutions, such as ammoniacal copper quat (ACQ), copper azole or copper citrate, are also widely available.  Whereas an untreated wood degrades within three to five years, treated timber can last up to sixty years!

Wood preservative manufacturers need to check the strength of the concentrated solutions they provide.  Their customers dilute these solutions and check their elemental contents before they use them to treat timber.  Samples of the treated timber will then be analyzed as sawdust to determine the efficiency of the treatment.

XRF for Wood Preservative Analysis

Oxford Instruments LabX3500 "CCA" comes ready for use because it is pre-calibrated for a wide range of wood preservatives and treated timber (sawdust).  The available calibrations include the following and are highlighted in the full application brief:

Solutions-% and Solutions KG/L (Cu version also)
     for the analysis of CCA and Cu solutions with concentrations expressed as % or kg/l
Sawdust-pcf and Sawdust-kg/m3 (Cu version also)
     analysis of CCA and Cu treated timber with timber density expressed respectively as pcf or kg/m3
CCA Poles-pcf and CCA Poles-kg/m3 (Cu version also)
     analysis of CCA or Cu treated timber; density calculated from length, diameter, and mass of pole
Penta Solutions
     for the analysis of Pentachlorophenol solutions with concentrations in %
Penta Sawdu.pcf and Penta Saw.kg/m3
     for the analysis of Penta treated timber with timber density expressed respetively as pcf or kg/m3
Penta Pole-pcf and Penta Pole kg/m3
     analysis of pentachlorophenol treated timber; density calculated by length, diameter, mass of pole

Sections included in the applications brief include:
XRF Analyzer Application Overview          Instrument Specification
          Sample Preparation
          Stability Data
          Performance and Results

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