Recent trends in capillary and micro-chip electrophoretic instrumentation for field-analysis

Technical advances in the development of field-deployable capillary and microchip electrophoretic instruments and reports of their deployment between 2013 and 2017 were reviewed. Strategies and considerations in the design of the injection, separation and detection hardware, chemistry and associated infrastructure were discussed from an in-field perspective, with portability, robustness and automation/“ease of use” featuring as key requirements. Integration of functionality is important for adequate in-field performance. Progress was made towards the use of multiple channel devices for increased throughput and/or resolving power, mixing devices for on-line/in-line sample derivatization, battery operation and temperature control. The strengths and weaknesses of the various approaches described in the literature are discussed from the perspective of in-field operation. An overview of the applications of the field electrophoretic instruments is provided, including environmental science and planetary investigation.     

Current air quality analytics and monitoring: A review

This review summarizes the different tools and concepts that are commonly applied in air quality monitoring. The monitoring of atmosphere is extremely important as the air quality is an important problem for large communities. Main requirements for analytical devices used for monitoring include a long period of autonomic operation and portability. These instruments, however, are often characterized by poor analytical performance. Monitoring networks are the most common tools used for monitoring, so large-scale monitoring programmes are summarized here. Biomonitoring, as a cheap and convenient alternative to traditional sample collection, is becoming more and more popular, although its main drawback is the lack of standard procedures. Telemonitoring is another approach to air monitoring, which offers some interesting opportunities, such as ease of coverage of large or remote areas, constituting a complementary approach to traditional strategies; however, it requires huge costs.     

便携式X射线荧光光谱仪在污染场地中重金属检测的应用

为探究便携式X射线荧光光谱法(Portable X-ray fluorescence spectrometry method, PXRF)测定结果的不确定度, 应用PXRF法和传统实验室方法对湖南某典型有色金属污染场地及周边土壤中的重金属进行测定,通过建立线性回归模型对比分析两种方法的测定数据,探究了PXRF法测定数据的准确程度和置信区间。结果表明,PXRF法原位、异位测定值与传统实验室方法测定值均能呈现较好的线性相关性,As、Cu、Pb、Cd等元素的决定性系数(R2)均大于0.70,其检测数据质量均能达到定量水平;PXRF法与实验室方法测定值间比率的置信区间结果显示,Cd元素的准确性最好,其次为Pb、Cu、As,比率置信区间分别为(0.57, 1.89)、(0.38, 2.22)、(0.31, 2.25)、(0.20, 4.53)。由此可见,PXRF法是一种方便快捷且相对准确的土壤重金属现场检测方法,可广泛地应用于污染场地调查和土壤修复工程实践中。     

Advances in stable and flexible perovskite solar cells

Roll-to-roll (R2R) production is an innovative approach and is fast becoming a very popular industrial method for high throughput and mass production of solar cells. Replacement of costly indium tin oxide (ITO), which conventionally has served as the transparent electrode would be a great approach for roll to roll production of flexible cost effective solar cells. Indium tin oxide (ITO) and fluorine-doped tin oxide (FTO) are brittle and ultimately limit the device flexibility. Perovskite solar cells (PSCs) have been the centre of photovoltaic research community during the recent years owing to its exceptional performance and economical prices. The best reported PSCs fabricated by employing mesoporous TiO₂ layers require elevated temperatures in the range of 400–500 °C which limits its applications to solely glass substrates. In such a scenario developing flexible PSCs technology can be considered a suitable and exciting arena from the application point of view, them being flexible, lightweight, portable, and easy to integrate over both small, large and curved surfaces.     

A novel non-invasive electrochemical biosensing device for in situ determination of the alcohol content in blood by monitoring ethanol in sweat

A non-invasive, passive and simple to use skin surface based sensing device for determining the blood's ethanol content (BAC) by monitoring transdermal alcohol concentration (TAC) is designed and developed. The proposed prototype is based on bienzyme amperometric composite biosensors that are sensitive to the variation of ethanol concentration. The prototype correlates, through previous calibration set-up, the amperometric signal generated from ethanol in sweat with its content in blood in a short period of time. The characteristics of this sensor device permit determination of the ethanol concentration in isolated and in continuous form, giving information of the BAC of a subject either in a given moment or its evolution during long periods of time (8 h). Moreover, as the measurements are performed in a biological fluid, the evaluated individual is not able to alter the result of the analysis. The maximum limit of ethanol in blood allowed by legislation is included within the linear range of the device (0.0005–0.6 g L⁻¹). Moreover, the device shows higher sensitivity than the breathalyzers marketed at the moment, allowing the monitoring of the ethanol content in blood to be obtained just 5 min after ingestion of the alcoholic drink. The comparison of the obtained results using the proposed device in the analysis of 40 volunteers with those provided by the gas chromatographic reference method for determination of BAC pointed out that there were no significant differences between both methods.     

便携式气相色谱-质谱联用仪的研制及应用

将双曲面三维离子阱质谱技术与低热容气相色谱技术相结合,研制了便携式气相色谱-质谱联用仪(GC-MS).此仪器主要由进样系统、低热容气相色谱模块、气质接口以及小型化离子阱质谱模块等构成,其主机重量小于14 kg,体积为44 cm×36 cm×22 cm,功耗小于100W.该仪器中的离子阱质谱仪系统具有15～550 amu...     

Construction of a portable sample preparation device with a magnetic poly(methacrylic acid‐co‐ethylene dimethacrylate) monolith as the extraction medium and its application in the enrichment of UV filters in water samples

A portable sample preparation device with a magnetic polymer monolith as the extraction medium was constructed. The monolith was synthesized by polymerizing methacrylic acid and ethylene dimethacrylate around a cylindrical magnet. In this way, the monolith with a magnetic core could be readily attached to the extraction device by magnetism. The constructed device was evaluated for the enrichment of UV filters in water samples, followed by high‐performance liquid chromatographic analysis. The extraction efficiency for the targets was satisfactory with no matrix interference. Good linearities were obtained for the UV filters with the correlation coefficients >0.9986. The limits of detection and quantification for the UV filters were 0.3–0.8 and 1.0–2.4 ng/mL, respectively. The recoveries of the UV filters from the spiked water samples at the concentration of 100 ng/mL were 95.3–101.7%, with relative standard deviations <10%. Accordingly, the proposed portable device was demonstrated to be suitable for on‐site simultaneous sampling, purification, and preconcentration within a single step.     

支持向量回归在人体血红蛋白无创检测中的应用

采用线性渐变滤光片(Linear variable filter, LVF),优化设计高性能、便携式的人体血液成分近红外检测设备,研究了支持向量回归(Support vector regression, SVR)模型对人体血红蛋白(Hemoglobin, Hb)的预测能力及稳定性,以实现贫血疾病的无创诊断.无创采集100位志愿者食指前端光谱信息并划分定标集、验证集1和2.应用网格搜索方法优选惩罚参数与核函数参数c=5.28, g=0.33,用以建立稳健的SVR模型.随后,分别对验证集1和2中Hb水平进行定量分析.实验结果表明: 预测标准偏差(RMSEP) 分别为10.20 g/L和10.85 g/L,相对预测标准偏差(R-RMSEP) 为6.85%和7.48%,测量精度较高且SVR模型对不同样品的适应性较强,基本满足临床检测要求.基于SVR算法自行设计的LVF型近红外光谱检测设备在贫血症的无创诊断中有着良好的应用前景.     

Green Approaches to Field Nitrate Analysis: An Electroanalytical Perspective

The different approaches that have been taken in the development of analytical methods for the determination of nitrate within the field are reviewed. The emphasis has been placed on providing a critical appraisal of the chemistry that underpins current commercial systems and the need to remove the dependence on heavy metal and concentrated acid components. The search for more environmentally acceptable and user friendly systems has long been pursued and the present communication seeks to explore the recent development in portable testing technologies and how they might evolve in the future. In particular, the role of electrochemical techniques in the latter are investigated and their potential application compared and contrasted with the more traditional wet chemical detection strategies.