Lu Li

Publications (2)8.1 Total impact

• Article: Eggshell membrane-based solid-phase extraction combined with hydride generation atomic fluorescence spectrometry for trace arsenic(V) in environmental water samples.

  Yongjiang Zhang, Weidong Wang, Lu Li, Yuming Huang, Jia Cao
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  ABSTRACT: The eggshell membrane (ESM) contains several surface functional groups such as amines, amides and carboxylic groups with potential as SPE adsorbent for the retention of target species of interest. In this paper, the potential use of ESM, a typical biomaterial, as solid-phase extraction (SPE) adsorbent is evaluated for analysis of trace arsenic(V) in environmental water samples in combination with hydride generation atomic fluorescence spectrometry (HG-AFS). In order to obtain the satisfactory recovery of arsenic(V), various parameters including the desorption and enrichment conditions such as pH, the flow rate and the volume of sample solution, the amount of ESM and the content of sodium chloride were systematically optimized and the effects of co-existed ions were also investigated in detail. Under the optimal conditions, arsenic(V) could be easily extracted by the ESM packed cartridge and the breakthrough adsorption capacity was found to be 3.9 microg g(-1). The favorable limit of detection (LOD) for arsenic(V) was found to be 0.001 microg L(-1) with an enrichment factor of 33.3, and the relative standard deviations (R.S.Ds) was 2.1% for 0.6 microg L(-1) arsenic (n=11). The reproducibility among columns was satisfactory (R.S.D. among columns is less than 5%). The proposed method has been successfully applied to analysis of arsenic(V) in aqueous environmental samples, which suggests the ESM can be an excellent SPE adsorbent for arsenic(V) pretreatment and enrichment from real water samples.
  Talanta 03/2010; 80(5):1907-12. · 3.79 Impact Factor
• Article: Hemimicelle capped functionalized carbon nanotubes-based nanosized solid-phase extraction of arsenic from environmental water samples.

  Lu Li, Yuming Huang, Yan Wang, Weidong Wang
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  ABSTRACT: The end functionalization of CNTs can introduce oxygen-containing negatively functional groups such as -COOH, -OH, or -CO on their surface site. If cationic surfactant such as cetyltrimethylammonium chloride (CTAC) was added to the functionalized CNTs, then interactions such as hydrophobic and ionic may lead to formation of hemimicelle/admicelle aggregates on the CNTs, a new kind of adsorbents, namely, the hemimicelle capped CMMWCNTs, is obtained. The application of the hemimicelle capped carbon nanotubes-based nanosized solid-phase extraction (SPE) adsorbents in environmental analysis is reported for the first time using arsenic as model target. The effect of adsorption and desorption conditions for arsenic including the amount of surfactant, initial pH of sample solution, the ultrasonic time of sample solution, the amount of electrolyte, flow rate, eluent and its amount were investigated and optimized prior to its determination by atomic fluorescence spectrophotometry (AFS). Arsenic can be quantitatively retained on the hemimicelle capped CMMWCNTs at pH 5-6 from sample volume up to 500 mL and then eluted completely with 2 molL(-1) HNO(3) in the presence of 10 mgL(-1) CTAC. The method detection limit for arsenic determination with AFS detection was 2ngL(-1), and the relative standard deviation (RSD, n=11) was 5.3% at the 0.5 microgL(-1) level. The recoveries of arsenic in the spiked environmental water samples ranged from 94% to 104.29% with 500 mL of water sample. The proposed method has been applied successfully to the analysis of arsenic in aqueous environmental samples, which demonstrates the hemimicelle capped CMMWCNTs can be an excellent SPE adsorbents for arsenic pretreatment and enrichment from real water samples.
  Analytica chimica acta 02/2009; 631(2):182-8. · 4.31 Impact Factor