Division 2.3.4.2 Interpretation of infra-red spectral data

Absorption shall be present in all regions of the analyte spectrum which correspond with an adequate peak in the reference spectrum of the calibration standard. A minimum of six adequate peaks is required in the infrared spectrum of the calibration standard. If there are less than six adequate peaks (7), the spectrum at issue cannot be used as a reference spectrum. The ‘score’, i.e. the percentage of the adequate peaks found in the infrared spectrum of the analyte, shall be at least 50. Where there is no exact match for an adequate peak, the relevant region of the analyte spectrum shall be consistent with the presence of a matching peak. The procedure is only applicable to absorption peaks in the sample spectrum with an intensity of a least three times the peak to peak noise.