共查询到18条相似文献，搜索用时 267 毫秒
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近红外光谱法在连翘提取物含量测定中的应用 总被引：1，自引：0，他引：1
利用近红外光谱法(NIR)快速测定连翘提取物中连翘苷含量.应用近红外光谱仪采集75份连翘提取物样品的近红外漫反射光谱,通过HPLC(high performance liquid chromatography)法测定各样品中连翘苷含量,结合偏最小二乘法建立了连翘苷含量的定量校正模型.结果显示,决定系数、校正均方差和预测均方差分别为0.973 1、0.119和0.110,表明该方法快速、简便、无损.结果准确可靠,为连翘提取物质量的快速评价和在线检测提供了参考和依据. 相似文献
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偏最小二乘法用于阿昔洛韦片的近红外漫反射快速、无损含量测定 总被引：2，自引：0，他引：2
目的:采用偏最小二乘法结合近红外漫反射光谱,建立阿昔洛韦片的快速无损含量测定模型.方法:以阿昔洛韦片为分析对象,用光纤探头测定近红外漫反射光谱.对光谱进行不同预处理方法建模并进行比较,多元校正模型为偏最小二乘法.结果:在11995.5～4246.7cm-1波长范围内采用一阶导数结合矢量归一化对光谱进行预处理,结果最优.定量模型的浓度范围为27%～53%.预示集平均回收率为98.69%,RSD为4.60%,RMSEP为0.0526.结论:近红外漫反射光谱法快速,简便,无损,能够用于阿昔洛韦片含量测定. 相似文献
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目的:近红外光谱分析(NIR)无损快速检测茶叶中咖啡碱成分,并建立模型。方法:按照国标GB/T8303-2002方法,将样品磨碎并测得化学值浓度,在近红外波段结合偏最小二乘法(PLS),建立20种不同浓度的茶叶近红外光谱和咖啡碱浓度的数学模型。结果:咖啡碱在1 900nm处建立的校正模型相关系数为0.931 7,均方根误差0.074 89。在2 212nm处所建立的校正模型相关系数为0.986 4,均方根误差为0.002 08。结论:近红外光谱法可作为一种快速有效地检测茶叶品质的方法。 相似文献
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金属材料的相变温度在日常检测中其检测结果易于出现波动,给生产造成不便.对取自两批料的TC4合金作相变温度检测时,发现所测得的相变温度相差15℃,试样整体化学成分含量并无较大差异.对样品不同部位进行扫描电镜能谱分析发现两样品微区Al、Ⅴ元素含量差别较大,结合合金元素含量对相变温度的影响,通过计算法得出因微区元素含量差异造成相变温度差值为18.75℃,与金相法所测得的结果一致,肯定了元素分布不均匀是造成样品相变温度检测结果出现差异的原因. 相似文献
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对盖胃平和阿司匹林两种西药中铝的含量进行测定,样品处理方法进行简化.用分光光度法测铝时,样品经硝酸和高氯酸消化后,在醋酸-醋酸铵缓冲溶液中,与铬天青-S及溴化十六烷基三甲基胺反应生成蓝色的三元络合物,测得最大吸收在630nm处,吸光度值在0~0.2ug/m L浓度范围内与Al3+含量线性关系良好,测得盖胃平中铝的含量为11.25mg/片,标识量为11.41mg/片,相对标准偏差仅为-1.48%,阿司匹林中铝的含量为5.6×10-3mg/片.该方法操作简单,加入的试剂少,试剂的污染小,减少了强酸带来的污染. 相似文献
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近红外光谱法快速测定六味地黄丸中水分含量 总被引：1，自引：0，他引：1
采集不同厂家不同批号六味地黄丸样品的近红外光谱图,将其经First Derivative+MSC预处理,采用Savitzky-Golay平滑法(5点3阶数据平滑)处理,以滤去噪声,在7 819~4 038 cm-1谱段范围内,选择前10个主因子数,利用偏最小二乘法建立六味地黄丸的近红外光谱与药典参考方法测得的水分含量之间的相关模型。建立的水分定量校正模型相关系数R2=0.990 4,内部交叉验证均方差(RMSECV)=0.250 2,预测均方差(RMSEP)=0.099 7,平均回收率为100.75%。本实验所建模型性能较好,对六味地黄丸中水分含量有很好的预测能力,可实现大批量样品的快速检测,对中药制剂的质量分析有一定的参考价值。 相似文献
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基于光谱技术的苹果糖度快速无损检测研究 总被引：2，自引：0，他引：2
论文以＂红富士苹果＂为样品,研究可见/近红外光谱技术进行苹果糖度的无损检测方法。选取30个苹果,用漫反射方式获取苹果的光谱曲线,用WAY-2S数字阿贝折射仪测量苹果的糖度,对光谱曲线进行平滑和消除噪声预处理后,用偏最小二乘法（PLS）对糖度建立相应的光谱预测模型。结果表明,糖度的模型稳定性较好,相关系数r达到了0.869,说明可见/近红外光谱技术可以进行苹果糖度的检测。 相似文献
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采用数据平滑和连续小波变换(CWT)的方法,对女贞子样品的近红外光谱数据(NIR)进行处理,建立了基于支持向量回归(SVR)和NIR快速测定齐墩果酸含量的方法.该方法用于测定女贞子样品中齐墩果酸的含量,与紫外光谱法测得的数据相比,回收率为95.54％～104.2％. 相似文献
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Measurement and analysis of soil nitrogen and organic matter content using near-infrared spectroscopy techniques 总被引：2，自引：0，他引：2
Near infrared reflectance （N1R） spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen （N） and organic matter （OM） content in a soil of Zhejiang Province, Hangzhou County. A total of 125 soil samples were taken from the field. Ninety-five samples spectra were used during the calibration and cross validation stage. Thirty samples spectra were used to predict N and OM concentration. NIR spectra of these samples were correlated using partial least square regression. The regression coefficients between measured and predicted values of N and OM was 0.92 and 0.93, and SEP （standard error of prediction） were 3.28 and 0.06, respectively, which showed that NIR method had potential to accurately predict these constituents in this soil. The results showed that NIR spectroscopy could be a good tool for precision farming application. 相似文献
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Hui-rong Xu Peng Yu Xia-ping Fu Yi-bin Ying 《Journal of Zhejiang University. Science. B》2009,10(2):126-132
The use of visible-near infrared (NIR) spectroscopy was explored as a tool to discriminate two new tomato plant varieties in China (Zheza205 and Zheza207).In this study,82 top-canopy leaves of Zheza205 and 86 top-canopy leaves of Zheza207 were measured in visible-NIR reflectance mode.Discriminant models were developed using principal component analysis (PCA),discriminant analysis (DA),and discriminant partial least squares (DPLS) regression methods.After outliers detection,the samples were randomly split into two sets,one used as a calibration set (n=82) and the remaining samples as a validation set (n=82).When predicting the variety of the samples in validation set,the classification correctness of the DPLS model after optimizing spectral pretreatment was up to 93%.The DPLS model with raw spectra after multiplicative scatter correction and Savitzky-Golay filter smoothing pretreatments had the best satisfactory calibration and prediction abilities (correlation coefficient of calibration (Rc)=0.920,root mean square errors of calibration=0.196,and root mean square errors of prediction=0.216).The results show that visible-NIR spectroscopy might be a suitable alternative tool to discriminate tomato plant varieties on-site. 相似文献
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Xia-ping Fu Jian-ping Li Ying Zhou Yi-bin Ying Li-juan Xie Xiao-ying Niu Zhan-ke Yan Hai-yan Yu 《Journal of Zhejiang University. Science. B》2009,10(2):120-125
The near infrared (NIR) spectroscopy technique has been applied in many fields because of its advantages of simple preparation,fast response,and non-destructiveness.We investigated the potential of NIR spectroscopy in diffuse reflectance mode for determining the soluble solid content (SSC) and acidity (pH) of intact loquats.Two cultivars of loquats (Dahongpao and Jiajiaozhong) harvested from two orchards (Tangxi and Chun'an,Zhejiang,China) were used for the measurement of NIR spectra between 800 and 2500 nm.A total of 400 loquats (100 samples of each cultivar from each orchard) were used in this study.Relationships between NIR spectra and SSC and acidity of ioquats were evaluated using partial least square (PLS) method.Spectra preprocessing options included the first and second derivatives,multiple scatter correction (MSC),and the standard normal variate (SNV).Three separate spectral windows identified as full NIR (800-2500 nm),short NIR (800～1100 nm),and long NIR (1100～2500 nm) were studied in factorial combination with the preprocessing options.The models gave relatively good predictions of the SSC of loquats,with root mean square error of prediction (RMSEP) values of 1.21,1.00,0.965,and 1.16 °Brix for Tangxi-Dahongpao,Tangxi-Jiajiaozhong,Chun'an-Dahongpao,and Chun'an-Jiajiaozhong,respectively.The acidity prediction was not satisfactory,with the RMSEP of 0.382,0.194,0.388,and 0.361 for the above four loquats,respectively.The results indicate that NIR diffuse reflectance spectroscopy can be used to predict the SSC and acidity of loquat fruit. 相似文献
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探索一种方便、快速、可靠的分析手段对于尿糖检测来说具有十分重要的意义.利用近红外光谱测试分析葡萄糖浓度为0 mg/dL-1 200 mg/dL的尿液样本,并通过偏最小二乘回归结合一阶导数光谱法构建尿糖浓度的预测模型,用于建模的光谱区域为900 nm-1 600 nm.研究表明,主成分个数为6时,训练集的线性相关系数达0.999 0,总体方均根误差为9.85 mg/dL,校验样本的总体方均根误差为26.51 mg/dL.鉴于近红外光谱技术具有方便、准确、廉价等优点,其可以为尿糖检测提供一种快速分析手段. 相似文献
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To evaluate the potential of FT-NIR spectroscopy and the influence of the distance between the light source/detection probe and the fruit for measuring the sugar content (SC) of Fuji apples, diffuse reflectance spectra were measured in the spectral range from 12500 to 4000 cm(1 at 0 mm, 2 mm, 4 mm and 6 mm distances. Four calibration models at four distances were established between diffused reflectance spectra and sugar content by partial least squares (PLS) analysis. The correlation coefficients (R) of calibrations ranged from 0.982 to 0.997 with SEC values from 0.138 to 0.453 and the SECV values from 0.74 to 1.58. The best model of original spectra at 0 mm distance yielded high correlation determination of 0.918, a SEC of 0.092, and a SEP of 0.773. The results showed that different light/detection probe-fruit distances influence the apple reflective spectra and SC predictions. 相似文献
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INTRODUCTION Recently increasing demands from consumerhave been observed for premium quality fruit witbetter taste at a higher price. Three major parameters determine the internal quality and the tastof apples. These are hardness, sugar content antitratable acidity, which are still determined destructively. Near-infrared spectroscopy (NIRS) habeen used to nondestructively measure internquality in a wide range of fruits and vegetablesuch as onions (Birth et al., 1985), cantaloupe (… 相似文献
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采用铬酸钾．罗丹明B化学发光体系对安乃近进行定量测定．在酸性溶液中,铬酸钾可以氧化安乃近并在荧光试剂罗丹明B存在的条件下,产生强烈的化学发光信号,根据光信号的大小可对安乃近的含量进行测定．其工作曲线的线性范围为O．03—15．0μg·mL^-1,检出限为0．01μg·mL^-1．该测定方法可用于片荆药物中安乃近的定量测定,结果令人满意． 相似文献
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Corn steep liquor(CSL) is an important raw material that has high nutritional value and serves as a nitrogen source.Biotin in CSL is especially of great importance to fermentation.In order to develop a fast,versatile,cheap,and environmentally safe analytical method for quantifying vitamins B2(VB2),B3(VB3),B6(VB6) and B7(VB7) in CSL,the near-infrared spectroscopy(NIR) measurements of 66 samples(22 batches) of CSL were analyzed by partial least-square regression(PLSR).Multivariate models developed in the NIR regions showed good predictive abilities for VB2,VB3,VB6 and VB7.Results confirmed the probability of the multivariate spectroscopic approach as a replacement for expensive and time-consuming conventional chemical methods. 相似文献