US Food and Drug Administration, Center for Drug Evaluation and Research, Division of Pharmaceutical Analysis, St. Louis, Missouri 63101, USA.
Anal Chem. 2011 Feb 1;83(3):1061-8. doi: 10.1021/ac1028598. Epub 2011 Jan 11.
We introduce a new method for analysis of X-ray fluorescence (XRF) spectra based on continuous wavelet transform filters, and the method is applied to the determination of toxic metals in pharmaceutical materials using hand-held XRF spectrometers. The method uses the continuous wavelet transform to filter the signal and noise components of the spectrum. We present a limit test that compares the wavelet domain signal-to-noise ratios at the energies of the elements of interest to an empirically determined signal-to-noise decision threshold. The limit test is advantageous because it does not require the user to measure calibration samples prior to measurement, though system suitability tests are still recommended. The limit test was evaluated in a collaborative study that involved five different hand-held XRF spectrometers used by multiple analysts in six separate laboratories across the United States. In total, more than 1200 measurements were performed. The detection limits estimated for arsenic, lead, mercury, and chromium were 8, 14, 20, and 150 μg/g, respectively.
我们介绍了一种基于连续小波变换滤波器的 X 射线荧光（XRF）光谱分析新方法，并将该方法应用于使用手持式 XRF 光谱仪测定药物材料中的有毒金属。该方法使用连续小波变换来滤除光谱中的信号和噪声分量。我们提出了一个极限测试，将感兴趣元素能量处的小波域信噪比与经验确定的信噪比决策阈值进行比较。极限测试具有优势，因为它不需要用户在测量之前测量校准样品，尽管仍建议进行系统适用性测试。极限测试在一项协作研究中进行了评估，该研究涉及美国六个不同实验室的五台不同的手持式 XRF 光谱仪，由多名分析人员使用。总共进行了超过 1200 次测量。分别估计砷、铅、汞和铬的检测限为 8、14、20 和 150μg/g。
