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在NaOH碱性介质中,维生素B1能将K3[Fe(CN)6]定量还原为K4[Fe(CN)6],根据Fe3+与K4[Fe(CN)6]反应生成可溶性普鲁士蓝的吸光度值,可间接测定出维生素B1的含量。在选定条件下,维生素B1在0.40~15.0mg·L-1范围内与吸光度(A)呈线性关系,相关系数R=0.9989,检出限为0.12mg·L-1,相对标准偏差(RSD)为1.75%(n=6)。表观摩尔吸光系数ε=4.3×104 L·mol-1·cm-1。该方法可用于药物中维生素B1含量的测定。 相似文献
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固蓝盐B分光光度法测定药物中抗坏血酸 总被引:12,自引:0,他引:12
探讨了一种简便的选择性高的药物中抗坏血酸的测定方法。该方法是基于在酸性介质中抗坏血酸和固蓝盐B的反应,产物的最大吸收为420nm.摩尔吸光系数为1.31×10~4L·mol~(-1)·cm~(-1).方法已应用于某些药物中抗坏血酸的测定,结果与碘量法一致,回收率为98.4%~105%,相对标准偏差低于3.7%。 相似文献
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菲林B近红外分光光度法测定维生素C 总被引:2,自引:0,他引:2
在pH 3的三氯乙酸酸性介质中,菲林B可以定量地将还原型维生素C氧化成脱氢型维生素C,利用脱氢型维生素C在920 nm处有最大吸光度,测定其含量,建立了一种测定维生素C的新方法,并研究了影响反应的各种因素。该方法对维生素C的检出限为0.17 mg/L;线性范围为0.5~10 mg/L,对水果中维生素C含量测定的RSD<2.31%;回收率为99.7%~101.1%,比2,4-二硝基苯肼分光光度法测定结果的相对偏差<±1.6%。 相似文献
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本文研究了罗丹明B与硫氰酸钼形成红色络合物的问题,提出了分光光度法直接测定天然水中微量钼的新方法,方法灵敏(_600~ε=1.88×10~5)干扰少,相对标准偏差小于7%。检出限为2ppb。 相似文献
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高灵敏度分光光度法测定痕量 Zn(Ⅱ) 的研究 总被引:9,自引:0,他引:9
研究了 Zn( ) - SCN-- Rh B- PVA高灵敏度显色反应体系 ,建立了光度法测定矿泉水中痕量 Zn( )的新方法。结果表明 ,在盐酸介质锌 -罗丹明 B络合物的表观摩尔吸光系数为 1 .58× 1 0 6L·mol-1·cm-1,Zn( )的质量浓度在0~ 2 .0 μg/ 50 m L范围内服从比尔定律。本方法已用于测定饮用水中总 Zn 相似文献
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研究了利血平与玫瑰精B的显色反应,建立了测定利血平的高灵敏分光光度法。在酸性条件下,利血平的水解产物和玫瑰精B形成具有正、负吸收峰的红色离子缔合物,最大正吸收波长位于490 nm,最大负吸收波长位于520 nm,表观摩尔吸光系数(ε)分别为1.20×105L.mol-1.cm-1(正吸收)和1.83×105L.mol-1.cm-1(负吸收),利血平在0~5.0μg/mL范围内遵从比尔定律。若采用正、负峰叠加测定,灵敏度可达3.00×105L.mol-1.cm-1。探讨了适宜的反应条件、主要分析特性及方法的精密度和可靠性。该法可用于市售利血平注射液中利血平含量的测定。 相似文献
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1 引 言作者曾开发出KMnO4 氧化 荧光分析法测定片剂中叶酸 (PGA)含量的荧光新体系。该法通过测定PGA的氧化产物蝶呤 6 羧酸的荧光强度 ,间接测定了PGA的含量。考虑到用H2 O2 氧化PGA ,分析其氧化产物蝶呤 6 甲醛的结构 ,也是强荧光性物质 ,也有可能用荧光测定法。为此本文详细研究了在NaAc HAc和NH4 Cl NH3·H2 O不同缓冲溶液中H2 O2 氧化PGA的最佳条件和荧光特性 ,PGA的检测限分别为 5 .2 μg/L(pH 5 .0 )、6.8μg/L (pH 10 .5 0 ) ,前者最佳pH范围较宽 ,抗干扰能力也明显强于… 相似文献
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Prasanthi Inakollu Thomas Philip Awadhesh K. Rai Fang-Yu Yueh Jagdish P. Singh 《Spectrochimica Acta Part B: Atomic Spectroscopy》2009
A comparative study of analysis methods (traditional calibration method and artificial neural networks (ANN) prediction method) for laser induced breakdown spectroscopy (LIBS) data of different Al alloy samples was performed. In the calibration method, the intensity of the analyte lines obtained from different samples are plotted against their concentration to form calibration curves for different elements from which the concentrations of unknown elements were deduced by comparing its LIBS signal with the calibration curves. Using ANN, an artificial neural network model is trained with a set of input data of known composition samples. The trained neural network is then used to predict the elemental concentration from the test spectra. The present results reveal that artificial neural networks are capable of predicting values better than traditional method in most cases. 相似文献
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人工神经网络在纸浆卡伯值光学定量分析中的应用 总被引:2,自引:0,他引:2
卡伯值 (硬度 )是纸浆的重要质量指标 ,是制浆过程控制的关键参数 .目前的测量方法包括化学分析法和光学分析法两大类型 ,国内大多数的制浆造纸厂采用离线的传统化学分析法来测定纸浆的卡伯值 ,需要比较长的时间 .而光学分析法因具有实时性好、精度和可靠性高等优点 ,已逐步用于卡伯值的在线测量和控制 .研究 [1] 发现 ,在 460~ 580 nm的可见光谱范围内 ,蒸煮液吸光度的变化可以表征纸浆中木素含量的变化 .本文将可见分光光谱技术应用于蒸煮液中木素含量的在线测量 ,根据蒸煮液在所选波段的吸光度来预测纸浆的卡伯值 ,建立纸浆卡伯值与蒸煮… 相似文献
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烃类混合气体的神经网络模型检测 总被引:2,自引:0,他引:2
八十年代末科学家模仿生物鼻研制一种传感器阵列与计算机模式识别的气体检测系统.传感器阵列相当于生物鼻的嗅觉细胞,计算机模式识别系统相当于嗅泡和大脑「‘].传感器阵列对气体的响应是一个多维空间的响应模式,这种响应模式经过一定的数学处理后可以实现气体的种类识别或浓度检测[’-‘j.传感器的响应和混合气体浓度之间呈非线性关系,这一特性给定量检测多组分气体混合物造成很大的限制.应用人工神经元网络技术(ANN)可以克服这一缺陷,并使检测气体的选择性大大提高.本工作运用ANN中的反向传播(BP)算法识别由16个不同… 相似文献
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《Analytical letters》2012,45(1):221-229
Abstract The use of artificial neural networks (ANN) in optimizing salicylic acid (SA) determination is presented in this paper. A simple and rapid spectrophotometric method for salicylic acid (SA) determination was carried out based on the complexation of salicylic acid–ferric(III) nitrate, SAFe(III). The SA forms a stable purple complex with ferric(III) nitrate at pH 2.45. The useful dynamic linear range is 0.01–0.35 g/L. It has a maximum absorption at 524 nm and the stability is more than 50 hours. The results were used for artificial neural networks (ANNs) training to optimize data. For training and validation purposes, a back‐propagation (BP) artificial neural network (ANN) was used. The results showed that ANN technique was very effective and useful in broadening the limited dynamic linear response range mentioned to an extensive calibration response (0.01–0.70 g/L). It was found that a network with 22 hidden neurons was highly accurate in predicting the determination of SA. This network scores a summation of squared error (SSE) skill and low average predicted error of 0.0078 and 0.00427 g/L, respectively. 相似文献
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Kuzmanovski I Zografski Z Trpkovska M Soptrajanov B Stefov V 《Fresenius' Journal of Analytical Chemistry》2001,370(7):919-923
A new chemometric method, which uses artificial neural networks (ANN), is presented for determination of the composition of urinary calculi. The selected constituents were whewellite, weddellite, and uric acid from which approximately 40% of the urinary calculi obtained from Macedonia patients are composed. The results for the synthetic mixtures were better then those obtained by partial least squares (PLS) regression or by the principal component regression (PCR), because neural networks have better prediction capacity. The generalization abilities of the optimized neural networks were checked using the standard addition method on carefully selected real natural samples. 相似文献
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神经网络方法在血管紧张素转换酶抑制剂定量构效关系建模中的应用 总被引:1,自引:0,他引:1
对20个ACEI化合物用量子化学方法进行结构优化并计算出10个参数,用9种不同隐含层节点数的BP神经网络研究了ACEI的定量构效关系,建立了节点为10/6/1的三层BP神经网络模型。结果表明:以量化理论计算所得参数可以构建合理的ACEI定量构效关系模型,神经网络模型M6的r2=0.995,S=0.050,6个验证集化合物的残差平方和为0.002,预测能力明显强于多元线形回归模型,亦优于同类文献报道,可作为ACEI研发领域中预测先导化合物活性的理论工具。 相似文献
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Gill Jatinder Singh Jagdev Ohunakin Olayinka S. Adelekan Damola S. 《Journal of Thermal Analysis and Calorimetry》2019,135(1):475-488
Journal of Thermal Analysis and Calorimetry - This paper experimentally investigated and also modeled using artificial neural networks (ANN) approach the energy analysis of a domestic refrigerator... 相似文献
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A promising way of increasing the selectivity and sensitivity of gas sensors is to treat the signals from a number of different gas sensors with pattern recognition (PR) method. A gas sensor array with seven piezoelectric crystals each coated with a different partially selective coating material was constructed to identify four kinds of combustible materials which generate smoke containing different components. The signals from the sensors were analyzed with both conventional multivariate analysis, stepwise discriminant analysis (SDA), and artificial neural networks (ANN) models. The results show that the predictions were even better with ANN models. In our experiment, we have reported a new method for training data selection, 'training set stepwise expending method' to solve the problem that the network can not converge at the beginning of the training. We also discussed how the parameters of neural networks, learning rate eta, momentum term alpha and few bad training data affect the performance of neural networks. 相似文献