Detection of trace materials with fourier transform infrared spectroscopy using a multi-channel detector
Detection of trace materials with fourier transform infrared spectroscopy using a multi-channel detector
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DOI：
10.1039/b511243e
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发表时间：
2006-01-01
期刊：
影响因子：
4.2
通讯作者：
Kazarian, SG
中科院分区：
文献类型：
--
作者：
Chan, KLA;Kazarian, SG
傅立叶变换红外光谱是材料表征最有力的手段之一。然而，这种分析工具的灵敏度往往非常有限，特别是对于红外吸收较弱的材料，或者当目标痕量材料的光谱带与主要组分的光谱带重叠时。幸运的是，对于异质样本，有机会通过使用成像方法来提高检测的灵敏度。本文探讨了利用基于焦平面阵列(FPA)探测器的FTIR成像方法来提高FTIR光谱对痕量物质检测的灵敏度的机会。使用羟丙基甲基纤维素(HPMC)中布洛芬的模型样品片来举例说明FTIR光谱的检测下限：(A)传统的碲化镉汞(MCT)检测器和(B)FPA检测器。比较了灵敏度水平，发现对于这组特定的样品，使用单元件MCT检测器使用衰减全反射(ATR)测量模式可以检测到的HPMC中布洛芬的最低浓度为0.35wt%。而使用FPA检测器时，已经在包含低至0.075 wt%的药物的样品中检测到药物的存在。还展示了使用多通道检测器提供的这种增强的灵敏度来探测在处理少量药物后留在手指表面的微量药物颗粒的应用。这些结果对法医、生物医学和药学研究具有广泛的意义。
FTIR spectroscopy is one of the most powerful methods for material characterization. However, the sensitivity of this analytical tool is often very limited especially for materials with weak infrared absorption or when spectral bands of the targeted trace material overlap with the spectral bands of major components. Fortunately, for heterogeneous samples, there is an opportunity to improve the sensitivity of detection by using an imaging approach. This paper explores the opportunity of enhancing the sensitivity of FTIR spectroscopy to detect trace amounts of materials using the FTIR imaging approach based on a focal plane array (FPA) detector. Model sample tablets of ibuprofen in hydroxypropyl methylcellulose ( HPMC) have been used to exemplify the detection limits of FTIR spectroscopy using: (a) a conventional mercury cadmium telluride (MCT) detector and (b) a FPA detector. The sensitivity level was compared and it has been found that for this particular set of samples, the lowest concentration of ibuprofen in HPMC that can be detected using attenuated total reflection (ATR) measuring mode with the single element MCT detector was 0.35 wt% while using the FPA detector, the presence of drug has been detected in a sample that contains as low as 0.075 wt% of drug. The application of using this enhanced sensitivity offered by the multi-channel detector to probe trace amounts of drug particles left on the surface of a finger after handling a small amount of the drug has also been demonstrated. These results have broad implications for forensic, biomedical and pharmaceutical research.