化学药中使用近红外高速鉴别检测方案

Application NoteNo. 200DR0188-E No.200DR0188-E sro Rapid Identification of an Illegal Drug using NIR(Identification of MDMA Tablet) Introduction Near-Infrared (NIR) spectroscopy has unique capabilities as compared to mid-infrared analysis which can often require extensivesample preparation to obtain an identifiable spectrum. As such， NIR can be useful for the non-destructive analysis of a specificsample area or provide an average of a larger sample area， depending upon the required analysis. In recent years， NIR spectroscopyhas been widely used for the examination of biological samples and quality control/analysis of food and medical products. Thediffuse reflectance technique is ideal for this method due to extremely simple sample handling such that rapid identification ofillegal drugs， such as MDMA， can be accomplished by using a search data library created using NIR diffuse reflectance. A diffuse reflection accessory (VIR-NRF-N) is used incombination with a portable Fourier Transform Near-InfraredSpectrometer (VIR-9650) and then by simply placing a tablet，such as MDMA， directly on the sample holder， a measurementcan be performed without further sample preparation..AnInGaAs detector is used to provide enhanced sensitivity and arapid scanning capability. Principal Components Analysis(PCA) was performed to simplify positive identification of anMDMA tablet. When the possible grouping of spectral datawas confirmed based on the PCA program， a library wasestablished. For establishing the PCA data library， 40 types oftablets were analyzed， namely 25 types of over-the-counterpharmaceuticals， such as gastrointestinal drugs， one type ofamphetamine (AP)， eight types of MDMA (street name：ecstasy)， three types ofmethamphetamine (MA)， and threetypes of MDA (street name： the love drug). The utility of asimple identificationsystem Wasexamined bytheinvestigation of the algorithm， the calculation parameters anda threshold established from comparison of the search resultsfrom randomly selected tablets. Figure 1 shows a photo ofthediffuse reflection system installed in the VIR-9650. Thetablets were placed on the sample holder directly， as shown inFigure 2. In the case of an extremely small tablet， unable to beplaced on the holder， the sample was placed in a test tube likethe one shown in Figure 3， and measured. Figure2： Measurement of a tablet Figure 1： VIR-9650 and the diffuse reflection accessory Figure 3： Measurement of crushed and powdered samples Figure 4 illustrates the PCA analysis results for an MDMAtablet. Figure 5 includes examples of the Near-Infrared spectrafor the 4 classes of illegal drugs. Sample identification can beaccomplished by using the region (indicated by the arrow)where the spectral absorptions can provide specific peaksdepending on the tablet component. The PCA method， however，les distinct discrimination between the various drugcomponents due to subtle variations in the NIR spectra. SinceNIR spectra do not provide specific discriminatory peaks likemid-IRspectra， thePCAmethod1offersannenhanceddiscrimination of the various drug components， strengtheningthe identification of the ‘unknown’drug tablet. The NIR diffusereflection system is ideal as a rapid analysis method because thetablet is simply placed on the accessory platform and the1S01required sample measurement time is only 10 seconds. Thismethod will become more powerful for sample identification asthe library data is expanded with additional standard sampledata. Figure 6 demonstrates a calibration model illustrating thecorrelation between tablets containing MDMA and quantitativeresults of these tablets using GC analysis. With a correlationcoefficient of R=0.966， these results demonstrate a sufficientcorrelation for performing sample quantitation.. This wouldmake it possible to analyze the amount of MDMA in illicittablets by linking the search results of the identificationprogram with the calibration model developed using GCanalysis. Figure 7 is an example of the program developed forthe identification of the drug formulations using the PCAsearch method. Conclusions We have demonstrated the use of a NIR analysis methodutilizing PCA discrimination for the identification of variousdrug formulations. The NIR system demonstrates a rapid， non-destructive analysis method for various drug tablets that can beextended to provide quantitative analysis of thee drugconcentration. Figure 5： Diffuse reflectance spectra of various street drugs Figure 4： PCA analysis results for street drugs Figure 6： Calibration curve of NIRand GC results for MDMA Figure 7： Confirmation test and quantitative analysis results copyrightOJASCO Corporation(/)