Rapid Determination of Organic Matter Fractions by Ozonation Chemiluminescence

2012 ◽  
Vol 468-471 ◽  
pp. 2842-2848 ◽  
Author(s):  
Yan Liu ◽  
Ping Ping Fan ◽  
Guang Li Hou ◽  
Ji Chang Sun ◽  
Yan Cheng ◽  
...  

Understanding marine biogeochemistry requires a network of global ocean in situ monitoring of various parameters on different scales in time and space. Among the various parameters involved in marine biogeochemistry, sediment chemistry is most important, and the organic matter fractions are the dominate factor in this parameter. However, classical methods of determining organic matter fractions consume a great deal of time and labor. In addition, some of these methods can produce high levels of pollution and are therefore not suitable for in situ studies. This study explored a method of rapid determination of organic matter fractions by ozonation chemiluminescence. In this method, the organic matter was separated into extractives, acid soluble fractions and acid insoluble fractions (AIF) using the classical method and then oxidized by ozone. The ozonation chemiluminescence characteristics of eight samples were subsequently used to set up a model to predict the concentrations of organic matter fractions. The model was tested using nine other organic samples and the results showed that it provided a better fit for the predicted acid soluble fractions. This study is the first to demonstrate the use of ozonation chemiluminescence for rapid determination of organic matter fractions; however, further study is required to enable its universal use.

2012 ◽  
Vol 468-471 ◽  
pp. 1850-1855 ◽  
Author(s):  
Meng De Liu ◽  
Ping Ping Fan ◽  
Liu Yan ◽  
Li Bin Du ◽  
Guang Li Hou ◽  
...  

Organic matter in soils and sediments is the key object of biogeochemistry in both terrestrial and marine ecosystems. Whether organic matter is the source or sink of carbon and nutrients can be predicted by its compositions and need continuous, long-term observations of organic matter compositions; therefore, in situ technologies are being investigated to meet the continuous, long-term observations. This study tried to explore a rapid determination of organic matter compositions by ozone chemiluminescence. After the soils or sediments were oxidized by ozone, their chemiluminescence characteristics such as luminescence maximum and time differed significantly. We hypothesized that the luminescence characteristics is controlled by the organic matter compositions. The soils and sediments were separated into extractives, acid soluble fractions (AS), and acid insoluble fractions (AIF), and then the original samples and their compositions were oxidized by ozone. Different organic matter compositions play a different role in the luminescence characteristics: extractives inhibited the luminescence maximum and luminescence time, AS increased the luminescence time and AIF increased the luminescence maximum. Results also showed that AIF can explain most variation of luminescence characteristics, suggesting that the luminescence characteristics are mainly controlled by the concentrations of AIF. Our study suggested that ozonaiton chemiluminescence have a strong potential to rapidly determine the chemistry of soils and sediments.


Author(s):  
Erick Gutierrez ◽  
Kevin Lin ◽  
Douglas DeVoto ◽  
Patrick McCluskey

Abstract Insulated gate bipolar transistor (IGBT) power modules are devices commonly used for high-power applications. Operation and environmental stresses can cause these power modules to progressively degrade over time, potentially leading to catastrophic failure of the device. This degradation process may cause some early performance symptoms related to the state of health of the power module, making it possible to detect reliability degradation of the IGBT module. Testing can be used to accelerate this process, permitting a rapid determination of whether specific declines in device reliability can be characterized. In this study, thermal cycling was conducted on multiple power modules simultaneously in order to assess the effect of thermal cycling on the degradation of the power module. In-situ monitoring of temperature was performed from inside each power module using high temperature thermocouples. Device imaging and characterization were performed along with temperature data analysis, to assess failure modes and mechanisms within the power modules. While the experiment aimed to assess the potential damage effects of thermal cycling on the die attach, results indicated that wire bond degradation was the life-limiting failure mechanism.


2015 ◽  
Vol 7 (7) ◽  
pp. 3006-3014 ◽  
Author(s):  
Beatriz Albero ◽  
Consuelo Sánchez-Brunete ◽  
Esther Miguel ◽  
José L. Tadeo

A simple and rapid method is proposed for the determination of fourteen emerging contaminants in water and different herbal infusions (tea, chamomile, linden-blossom and pennyroyal).


2021 ◽  
Vol 2 (4) ◽  
pp. 26-35
Author(s):  
Muhammad Ramzan ◽  

Basic soil composition, or more precisely, soil organic matter, soil clay mineralogy and soil texture have been in the core of most infrared spectroscopy research for soils. Of course, nutrient availability, soil structure, soil microbial activity and soil fertility have also been a major subject of interest over the past two decades. The determination of soil nutrients is now becoming a routine work at large scale to gain high yield. The large number of soil nutrients determining techniques are used. The current paper presented that among tested techniques, Near-infrared reflectance spectroscopy (NIRS) is a best technique which has been used widely with minimum time, low in cost, ecofriendly and rapid determination of chemical, physical properties and organic matter present in soil. Obviously, this useful technique can be used to estimate properties such as mineral composition, SOM, water, percentage of carbon, nitrogen and clay content. It could be used directly in soil mapping, for monitoring soil, for making inferences about its quality and function, and making geomorphological interpretations of its distribution. The development of most accurate and trustworthy NIRS approaches are required.


Separations ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 149
Author(s):  
Sara Bocanegra-Rodríguez ◽  
Carmen Molins-Legua ◽  
Pilar Campíns-Falcó

We propose a portable sensor, obtained by embedding luminol into the tetraethylorthosilicate/trietoxymethylsilane (TEOS/MTEOS) composite, for the quantitative determination of organic amino nitrogen and ammonium in water with the goal of achieving low levels of concentration. The method is based on the reaction between amino nitrogen compounds and hypochlorite to produce chloramino derivatives. Then, the remaining hypochlorite reacts with luminol sensor by producing a luminescence signal, which was measured by using a portable luminometer, being inversely proportional to nitrogen concentration. The liberation of the luminol from sensor is higher than 90% and the sensor is stable for at least a week at room temperature. This portable method was successfully validated and applied to the analysis of several real waters: fountain, river transition, lagoon, and seawater with recovery values between 92% and 112%, which indicated that the matrix effect was absent. The achieved limit of detection was around 10 µg·L−1, expressed as N. This sensor allows in situ monitoring owing to its simplicity, rapidity, and portability.


Author(s):  
Edwards Taufiqurrahman ◽  
A’an J. Wahyudi ◽  
Yukio Masumoto

It has been widely known that the Indonesian Throughflow (ITF) is an important inter-ocean connection with unique and complex oceanographic and geographic conditions, as well as a strong relation to both regional and global ocean currents and climate systems. Many studies on characteristics, mechanisms, and impacts of the ITF have been conducted, mainly focusing on the ITF pathways, transport, water mass mixing processes, and their variability in connection with monsoons and climate systems. In this paper, we summarize some of the critical aspects related to ocean conditions within the Indonesian Seas and the Indonesian Throughflow, with the main focus on studies of marine biogeochemistry in a region affected by the ITF. Although the biogeochemical cycle is one of the key research topics that are needed to advance our ocean understanding, studies on marine biogeochemistry within the Indonesian Seas are quite limited due to less observed data compared to the physical parameters. Further studies on biogeochemistry and efforts to conduct in situ and remotely sensed observations in this region are strongly required. Here, we propose several biogeochemical observations correlated to the ITF.


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