一种提高化妆品中甲醛含量检测的稳定性和灵敏度的双波长光谱方法

提出了一种基于双波长光谱法(以500 nm吸光度为基准并结合414 nm处的吸光度)快速测定化妆品中甲醛含量的方法。结果表明:采用单波长的计算方法(不考虑基线漂移)产生的误差时,平行试验结果之间的相对标准偏差(RSD)可达11.5%,而该方法的RSD最大仅为0.46%。同时该方法能够有效地校正扣除萃取液颜色和基线漂移的影响,且定量下限为7.4 mg/kg。该方法具有分析时间短、操作便捷、灵敏度高、结果准确的优点,适用于化妆品中甲醛的检测。     

Dual-Wavelength Spectrophotometry

At present, dual-wavelength spectrophotometry is probably the least well known of the techniques of absorption spectrophotometry. However, recent improvements in application techniques have shown that for various organic and inorganic materials dual-wavelength spectrophotometry can provide higher sensitivity and selectivity than conventional spectrophotometry. This article reviews the principles and scope of dual-wavelength spectrophotometry, including derivative absorption spectrophotometry, in the hope that these techniques may be adopted more frequently in the future for resolving many analytical problems.     

测定可见光区分光光度系组成的新方法

本文报道一种测定二元分光光度系组成的新方法,原理新颖,为作者首创,采用双波长分光光度技术消除显色产物的影响,直接测定与显色剂平衡浓度相对应的吸光度,通过简单的计算即可求得产物组成。     

高酸度条件下单波长、双峰双波长分光光度法测定铬(Ⅵ)

铬(Ⅵ)的测定,在金属材料的分析中具有重要意义。目前,铬的测定仍采用二苯卡巴肼法,该法的灵敏度虽较高(ε=34600),但由于显色剂的稳定性很差,显色剂溶液和工作曲线需当天配制和绘制,除给操作带来许多麻烦外,还造成大量试剂的浪费。     

Organic Printed Core–Shell Heterostructure Arrays: A Universal Approach to All-Color Laser Display Panels

A universal approach is demonstrated for realizing dual-wavelength lasing in organic core–shell structured microlaser arrays, which show great promise in serving as all-color laser display panels. By alternately printing hydrophilic and hydrophobic laser dye solutions on preprocessed substrates, precisely patterned core–shell heterostructure arrays were obtained. The spatially separated core and shell independently function as optical resonators to support dual-wavelength tunable lasing in each heterostructure. Such a general method enables to flexibly control the lasing wavelength of the core–shell microlasers across a wide spectral range by systematically designing the gain media. Using as-prepared microlaser arrays as display panels, full-color laser displays were achieved with a color gamut much larger than that of standard RGB space. These results provide insights for design concepts and device construction for novel optoelectronic applications.     

双波长分光光度法测定有机弱酸弱碱的解离常数

本文提出了一种测定有机一元弱酸弱碱解离常数的新方法———双波长分光光度法。该方法是在选定的一对工作波长下测定相同浓度不同pH值的有机一元弱酸弱碱水溶液的吸光度,利用所推导的公式作图求得pKa(或pKb)。利用本方法测定了甲基橙、溴甲酚绿、苯酚和苯胺等多种常见的有机一元弱酸弱碱的解离常数,结果十分满意。与传统的单波长分光光度法相比,双波长法测定结果的精密度和准确度更高。     

双波长分光光度法同时测定灌木饲料中的铁和铝

利用铁、铝与邻苯二酚紫（PCV）形成的络合物的最大吸收波长相差30nm的光谱性质，建立了同时测定铁和铝的双波长分光光度法，并对络合物的形成条件及相互干扰情况进行研究，方法用于灌木饲料样品中铁和铝测定。