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981.
基于K-S算法的水质硝酸盐含量光谱检测方法研究 总被引:2,自引:0,他引:2
应用紫外光谱对水体中的总氮进行测定,常规的测定方法在分析精度上依赖于所建立的光谱数学模型.测量过程中所依据的紫外光谱数据波段较多,模型的建立所依据的测试样本也比较多,因而很容易引入干扰光谱信息.对水质样本的原始光谱进行一阶微分处理后,采用Kennard-Stone算法对41个样本进行优选,选出30个作为训练集,剩余11... 相似文献
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This work reports a sequential-injection analysis (SIA) method with chemiluminescence (CL) detection for the rapid assay of the total antioxidant capacity (TAC) in wines. The method exploited the Co(II)-catalysed CL reaction of luminol with hydrogen peroxide in alkaline medium. Zones of sample, hydrogen peroxide, catalyst (Co(II) solution) and alkaline luminol were sequentially aspirated into the holding coil of the SIA manifold. Then, the flow was reversed and the stacked zones were directed to the CL detector. As the zones overlapped, antioxidants in the samples scavenged a portion of hydrogen peroxide and the decrease in the CL intensity was monitored and related to the TAC. The chemical and geometric conditions were studied and the method was validated in terms of linearity, accuracy (trueness and precision), matrix effects, signal additivity and robustness. The reproducibility of the method (expressed as the between-days % relative standard deviation) was between 2.5 and 3.4% and the trueness (expressed as the % recovery in wines spiked with gallic acid) was in the range 96.7-97.3%. The sampling frequency was 60 samples h−1. The proposed SIA-CL method was compared with the DPPH method and the Folin-Ciocalteau (FC) method for the analysis of 25 wine samples. 相似文献
987.
本文旨在纠正一种在化学家中流传甚久的对统计数学中相关系数的错误理解.这种理解认为在数据拟合中单凭相关系数R大于某个人为指定值就可以判定数据拟合的优劣. 相似文献
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《Analytical letters》2012,45(12):1784-1804
Abstract High-performance liquid-chromatographic (HPLC) methods were validated for determination of pravastatin sodium (PS), fluvastatin sodium (FVS), atorvastatin calcium (ATC), and rosuvastatin calcium (RC) in pharmaceuticals. Two stability-indicating HPLC methods were developed with a small change (10%) in the composition of the organic modifier in the mobile phase. The HPLC method for each statin was validated using isocratic elution. An RP-18 column was used with mobile phases consisting of methanol–water (60:40, v/v, for PS and RC and 70:30, v/v, for FVS and ATC). The pH of each mobile phase was adjusted to 3.0 with orthophosphoric acid, and the flow rate was 1.0 mL/min. Calibration plots showed correlation coefficients (r) > 0.999, which were calculated by the least square method. The detection limit (DL) and quantitation limit (QL) were 1.22 and 3.08 µg/mL for PS, 2.02 and 6.12 µg/mL for FVS, 0.44 and 1.34 µg/mL for ATC, and 1.55 and 4.70 µg/mL for RC. Intraday and interday relative standard deviations (RSDs) were <2.0%. The methods were applied successfully for quantitative determination of statins in pharmaceuticals. 相似文献
990.
《Analytical letters》2012,45(7):1779-1790
Abstract A quantitative simultaneous extraction procedure of copper, silver and gold cations from aqueous thiocyanate solutions into Methyl Isobutyl Ketone (MIBK) is described. the effects of pH, thiocyanate and 2,2′-Dipyridyl-2-py-ridylhydrazone (DPPH) concentration were studied. Tolerance amounts for many diverse cations and anions have been determined. Finally, a procedure for the determination of IB Group elements is recommended, by extaction-AAS. 相似文献