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:
Multiresidue analysis of aromatic organochlorines in soil by gas chromatography-mass spectrometry and QuEChERS extraction based on water/dichloromethane partitioning. Comparison with Accelerated Solvent Extraction
03 March 2012, 22:45:49
Publication year: 2012
Source: Talanta, Available online 3 March 2012
Florent Rouvière, Audrey Buleté, Cécile Cren-Olivé, Carine Arnaudguilhem
A novel multiresidue method was developed for the simultaneous analysis of 34 organochlorines, including chlorobenzenes, chlorophenols, chlorinated hydrocarbons and chlorinated olefins, in soil by GC-MS, using a QuEChERS-based extraction. The conventional QuEChERS method was optimised and, for the first time, the use of a non miscible-water solvent was required. The method was compared to ASE extraction, versatile technique widely used for the soils’ extraction and QuEChERS-based method was shown to be the most efficient in terms of recoveries, simplicity and rapidity. For ASE, recoveries between 42 and 85% were obtained for the majority of the compounds. However, due to the high pressure, all volatile compounds were lost. In opposite, QuEChERS extraction allowed detection and quantification of all the compounds with recoveries between 60 and 100%. Moreover, no additional clean up by dispersive SPE on PSA was necessary, which allowed reducing the cost of the analysis.Performance of the method was assessed. The method was linear over the range of concentration of 10-5000 μg Kg. Precision, expressed as intra-day precision and inter-day variation was verified at three concentrations. Limits of detection were from 2 to 50 μg Kgand limits of quantification from 7 to 170 μg Kgfor the majority of the compounds (chlorobenzenes and chlorinated hydrocarbons and olefins), except for chlorophenols. The method was further applied to different soils coming from a contaminated industrial site, where a new environmental remediation process, using phytoremediation, was tested. The results showed that the method could be applied to any kind of soils (mineral or organic) and was appropriate to very volatile compounds which were not available with conventional technique.
Source: Talanta, Available online 3 March 2012
Florent Rouvière, Audrey Buleté, Cécile Cren-Olivé, Carine Arnaudguilhem
A novel multiresidue method was developed for the simultaneous analysis of 34 organochlorines, including chlorobenzenes, chlorophenols, chlorinated hydrocarbons and chlorinated olefins, in soil by GC-MS, using a QuEChERS-based extraction. The conventional QuEChERS method was optimised and, for the first time, the use of a non miscible-water solvent was required. The method was compared to ASE extraction, versatile technique widely used for the soils’ extraction and QuEChERS-based method was shown to be the most efficient in terms of recoveries, simplicity and rapidity. For ASE, recoveries between 42 and 85% were obtained for the majority of the compounds. However, due to the high pressure, all volatile compounds were lost. In opposite, QuEChERS extraction allowed detection and quantification of all the compounds with recoveries between 60 and 100%. Moreover, no additional clean up by dispersive SPE on PSA was necessary, which allowed reducing the cost of the analysis.Performance of the method was assessed. The method was linear over the range of concentration of 10-5000 μg Kg. Precision, expressed as intra-day precision and inter-day variation was verified at three concentrations. Limits of detection were from 2 to 50 μg Kgand limits of quantification from 7 to 170 μg Kgfor the majority of the compounds (chlorobenzenes and chlorinated hydrocarbons and olefins), except for chlorophenols. The method was further applied to different soils coming from a contaminated industrial site, where a new environmental remediation process, using phytoremediation, was tested. The results showed that the method could be applied to any kind of soils (mineral or organic) and was appropriate to very volatile compounds which were not available with conventional technique.
Highlights
► Optimisation of QuEChERS method for the analysis of organochlorines and phenols ► Compared to ASE, the developed QuEChERS method is rapid and easy to use ► Better recoveries with QuEChERS-based method than ASE ► Contrary to conventional methods, no water elimination. Then, no loss of volatiles ► QuEChERS-based method provides clean extracts with few matrix effectsEnhanced fluorescence sensing of melamine based on thioglycolic acid-capped CdS quantum dots
03 March 2012, 22:45:49
Publication year: 2012
Source: Talanta, Available online 2 March 2012
Guang-Li Wang, Huan-Jun Jiao, Xiao-Ying Zhu, Yu-Ming Dong, Zai-Jun Li
A sensitive and simple method for the determination of melamine (MA) was developed based on the fluorescence enhancement effect of MA for thioglycolic acid-capped (TGA-capped) CdS quantum dots (QDs). Under optimum conditions, a good linear relationship was obtained from 2.0 × 10to 5.0 × 10 M. The detection limit was 1.0 × 10 M, which was much lower than the safety limit (2.5 ppm in USA and the UK; 1 ppm for infant formula in China). The solution pH, the adding sequence of the buffer solution and MA and surface modifiers of CdS QDs greatly influenced the enhancement extent of MA for CdS QDs. The fluorescence enhancement was attributed to the surface passivation of the surface states of QDs by amine group of MA. The method was applied to detect MA in raw milk with satisfactory results. The proposed method manifested several advantages such as high sensitivity, short analysis time, low cost and ease of operation.
Source: Talanta, Available online 2 March 2012
Guang-Li Wang, Huan-Jun Jiao, Xiao-Ying Zhu, Yu-Ming Dong, Zai-Jun Li
A sensitive and simple method for the determination of melamine (MA) was developed based on the fluorescence enhancement effect of MA for thioglycolic acid-capped (TGA-capped) CdS quantum dots (QDs). Under optimum conditions, a good linear relationship was obtained from 2.0 × 10to 5.0 × 10 M. The detection limit was 1.0 × 10 M, which was much lower than the safety limit (2.5 ppm in USA and the UK; 1 ppm for infant formula in China). The solution pH, the adding sequence of the buffer solution and MA and surface modifiers of CdS QDs greatly influenced the enhancement extent of MA for CdS QDs. The fluorescence enhancement was attributed to the surface passivation of the surface states of QDs by amine group of MA. The method was applied to detect MA in raw milk with satisfactory results. The proposed method manifested several advantages such as high sensitivity, short analysis time, low cost and ease of operation.
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