| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1180377 | Chemometrics and Intelligent Laboratory Systems | 2015 | 10 Pages |
•UV-Visible spectroscopy could differentiate between spectral of ACQ wood preservative components.•UV-Visible spectroscopy coupled with chemometrics could assay ACQ wood preservative.•PLS models could predict concentrations of at least two ACQ constituents.
This study investigated the ability of ultra violet-visible (UV-Visible) spectroscopy to characterize and predict the concentration of major chemical components: moldicide, didecylalkylammonium compounds (DDAC), and copper in alkaline copper quaternary (ACQ) preservatives. Twenty replicates of four different concentrations (percentage v/v) of 0.5%, 1.0%, 1.5%, and 2.5% were scanned on a UV-NIR spectrophotometer. Copper concentrations (ppm) in the preservative solutions were determined by inductively coupled plasma-emission spectroscopy (IPC-ES), and DDAC concentration in each preservative solution was determined according to the AWPA Standard A17-09. UV-Visible spectroscopy accurately differentiated between the spectral characteristics of the major ACQ chemical constituents: moldicide, DDAC, and copper in ACQ preservative. Soft independent modeling of class analogies (SIMCA) and partial least square discriminant analysis (PLS-DA) classification model developed reliably discriminate between spectra of different concentration of moldicide with low error. Partial least squares (PLS) regression models developed could predict the concentrations of at least two (DDAC and copper) components within the ACQ formulation. Preprocessing the spectra data matrix using the Savitzky–Golay 1st derivative greatly improved PLS regression models developed for DDAC and copper using the full spectral region (250–800 nm). PLS models developed using a reduced spectra wavelength (300–600 nm) region were useable and accurate in its predictive ability (R2 > 0.86) for both chemical constituents. Overall, this study showed that UV-Vis spectroscopy coupled with chemometrics can be used to quantify the chemical constituents of ACQ.
