World Congress on Biosensors 2014

World Congress on Biosensors 2014
Biosensors 2014

Tuesday 27 August 2013

Just Published: Analytica Chimica Acta

A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:

Selected papers from the latest issue:

Applications of in vivo and in vitro solid-phase microextraction techniques in plant analysis: A review

26 August 2013, 20:49:11
Publication date: 10 September 2013
Source:Analytica Chimica Acta, Volume 794
Author(s): Fang Zhu , Jianqiao Xu , Yuanyuan Ke , Siming Huang , Feng Zeng , Tiangang Luan , Gangfeng Ouyang
As a very popular sample preparation technique, solid-phase microextraction (SPME) coupled with various analytical instrumentation, has been widely used for the determination of trace levels of different plant compounds, such as volatile organic compounds (VOCs) emitted from the different plant organs, and environmental contaminants in plants. In this review, recent applications of in vitro and in vivo SPME in plant analysis are discussed and summarized according to the different organs of plants, including fruits, flowers, leaves, stems, roots and seeds, and the whole plant as well. Future developments and applications of SPME in plant analysis, especially in vivo sampling approaches, are also prospected.

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Determination of Pd, Rh, Pt, Au in road dust by electrothermal vaporization inductively coupled plasma mass spectrometry with slurry sampling

26 August 2013, 20:49:11
Publication date: 10 September 2013
Source:Analytica Chimica Acta, Volume 794
Author(s): Wan-Hsuan Hsu , Shiuh-Jen Jiang , A.C. Sahayam
Inductively coupled plasma mass spectrometry coupled with ultrasonic slurry sampling electrothermal vaporization (USS-ETV-ICP-MS) has been applied to determine Pd, Rh, Pt and Au in 0.5% m/v slurries of several road dust samples. 2% m/v ammonium pyrrolidine dithiocarbamate (APDC) was used as the modifier to enhance the ion count. The influence of instrument operating conditions, slurry preparation and interferences on the ion count was reported. This method has been applied to the determination of Pd, Rh, Pt and Au in BCR 723 Road Dust and NIST SRM 2709 San Joaquin Soil reference materials and two road dust samples collected locally. The analysis results of the standard reference materials agreed with the certified values. Precision between sample replicates was better than 10% for all the determinations. The method detection limits estimated from standard addition curves were 0.9, 0.4, 0.6 and 0.4ngg−1 for Pd, Rh, Pt and Au, respectively, in original dust samples.

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Extension and application of multivariate curve resolution-alternating least squares to four-way quadrilinear data-obtained in the investigation of pollution patterns on Yamuna River, India—A case study

26 August 2013, 20:49:11
Publication date: 10 September 2013
Source:Analytica Chimica Acta, Volume 794
Author(s): Amrita Malik , Roma Tauler
This study focuses on the development and extension of Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) to the analysis of four-way datasets. The proposed extension of the MCR-ALS method with non-negativity and the newly developed quadrilinear constraints can be exploited to summarize and manage huge multidimensional datasets and resolve their four way component profiles. In this study, its application is demonstrated by analyzing a four-way data set obtained in a long term environmental monitoring study (15 sampling sites×9 variables×12 months×7 years) belonging to the Yamuna River, one of the most polluted rivers of India and the largest tributary of the Ganges river. MCR-ALS resolved pollution profiles described appropriately the major observed changes on pH, organic pollution, bacteriological pollution and temperature, along with their spatial and temporal distribution patterns for the studied stretch of Yamuna River. Results obtained by MCR-ALS have also been compared with those obtained by another multi-way method, PARAFAC. The methodology used in this study is completely general and it can be applied to other multi-way datasets.

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Automatic identification of novel bacteria using Raman spectroscopy and Gaussian processes

26 August 2013, 20:49:11
Publication date: 10 September 2013
Source:Analytica Chimica Acta, Volume 794
Author(s): Michael Kemmler , Erik Rodner , Petra Rösch , Jürgen Popp , Joachim Denzler
Raman spectroscopy is successfully used for the reliable classification of complex biological samples. Much effort concentrates on the accurate prediction of known categories for highly relevant tasks in a wide area of applications such as cancer detection and bacteria recognition. However, the resulting recognition systems cannot always be directly used in practice since unseen samples might not belong to classes present in the training set. Our work aims to tackle this problem of novelty detection using a recently proposed approach based on Gaussian processes. By learning novelty scores for a large bacteria Raman dataset comprising 50 different strains, we analyze the behavior of this method on an independent dataset which includes known as well as unknown categories. Our experiment reveals that non-parametric methods such as Gaussian processes can be successfully applied to the task of finding unknown bacterial strains, leading to encouraging results motivating their further utilization in this area.

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Highlights


A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B

26 August 2013, 20:49:11
Publication date: 10 September 2013
Source:Analytica Chimica Acta, Volume 794
Author(s): Habib Bagheri , Rasoul Daliri , Ali Roostaie
A novel Fe3O4–poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe3O4/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample pH, ionic strength, extraction time and stirring rate were optimized. Under the optimum condition, a linear spiked calibration curve in the range of 0.35–5.00μgL−1 with R 2 =0.9991 was obtained. The limits of detection (3S b) and limits of quantification (10S b) of the method were 0.10μgL−1 and 0.35μgL−1 (n =3), respectively. The relative standard deviation for water sample with 0.5μgL−1 of RhB was 4.2% (n =5) and the absolute recovery was 92%. The method was applied for the determination of rhodamine B in dishwashing foam, dishwashing liquid, shampoo, pencil, matches tips and eye shadows samples and the relative recovery percentage were in the range of 94–99%.

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A sensitive flow-batch system for on board determination of ultra-trace ammonium in seawater: Method development and shipboard application

26 August 2013, 20:49:11
Publication date: 10 September 2013
Source:Analytica Chimica Acta, Volume 794
Author(s): Yong Zhu , Dongxing Yuan , Yongming Huang , Jian Ma , Sichao Feng
Combining fluorescence detection with flow analysis and solid phase extraction (SPE), a highly sensitive and automatic flow system for measurement of ultra-trace ammonium in open ocean water was established. Determination was based on fluorescence detection of a typical product of o-phthaldialdehyde and ammonium. In this study, the fluorescence reaction product could be efficiently extracted onto an SPE cartridge (HLB, hydrophilic–lipophilic balance). The extracted fluorescence compounds were rapidly eluted with ethanol and directed into a flow cell for fluorescence detection. Compared with the common used fluorescence method, the proposed one offered the benefits of improved sensitivity, reduced reagent consumption, negligible salinity effect and lower cost. Experimental parameters were optimized using a univariate experimental design. Calibration curves, ranging from 1.67 to 300nM, were obtained with different reaction times. The recoveries were between 89.5 and 96.5%, and the detection limits in land-based and shipboard laboratories were 0.7 and 1.2nM, respectively. The relative standard deviation was 3.5% (n =5) for an aged seawater sample spiked with 20nM ammonium. Compared with the analytical results obtained using the indophenol blue method coupled to a long-path liquid waveguide capillary cell, the proposed method showed good agreement. The method had been applied on board during a South China Sea cruise in August 2012. A vertical profile of ammonium in the South East Asia Time-Series (SEATS, 18° N, 116° E) station was produced. The distribution of ammonium in the surface seawater of the Qiongdong upwelling in South China Sea is also presented.

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Matrix-assisted laser desorption ionization mass spectrometry for identification of shrimp

26 August 2013, 20:49:11
Publication date: 10 September 2013
Source:Analytica Chimica Acta, Volume 794
Author(s): Venkatesulu Salla , Kermit K. Murray
Matrix-assisted laser desorption ionization (MALDI) time of flight mass spectrometry was used to identify shrimp at the species level using commercial mass spectral fingerprint matching software (Bruker Biotyper). In the first step, a mass spectrum reference database was constructed from the analysis of six commercially important shrimp species: Litopenaeus setiferus, Farfantepenaeus aztecus, Sicyonia brevirostris, Pleoticus robustus, Pandalopsis dispar and Pandalus platyceros. This step required a desalting procedure for optimum performance. In the second step, the reference database was tested using 74 unknown shrimp samples from these six species. Correct identification was achieved for 72 of 74 samples (97%): 72 samples were identified at the species level and 2 samples were identified at the genus level using the manufacturer's log score specifications. The MALDI fingerprinting method for the identification of shrimp species was found to be reproducible and accurate with rapid analysis.

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