Abstract
Near infra-red (NIR) reflectance spectroscopy has been used for rapidly and reproducibly measuring the NIR spectra of mainstream smoke collected on Cambridge filter pads and quantifying the chemical composition from the spectral data. This technique has four main advantages: speed, simplicity of sample preparation, multiple analytes from one scan of a sample, and non-destruction of the sample. The study has been conducted in our research laboratory to define the possible use of NIRA (Near Infra-red Reflectance Analysis) as an instrumental screening tool for analysing mainstream smoke collected on Cambridge Filter pads. A major advantage of this method is that it eliminates the use of dangerous chemicals such as cyanogen bromide or chloride involved with some standard assays. Using specific wavelengths, we are able to determine with acceptable accuracy water, nicotine and tar. Correlation coefficients of NIRA results compared with those obtained by standard methods are better than 0.9 for all analyses. NIRA cannot replace ISO standard methods, flow analysis or chromatography, but as a reliable screening analysis, it could reduce the routine work load by 80 %. These savings could be achieved by prescreening samples with NIRA and analysing only suspect samples by distillation or continuous flow analysis.