Yulin Normal College

Yulin, China

Yulin Normal College

Yulin, China

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A new method of hollow fiber supported liquid membrane extraction (HF-SLME) coupled with thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) for the speciation of Sb(III) and Sb(V) in environmental and biological samples has been developed. The method is based on the complex of Sb(III) with sodium diethyldithiocarbamate (DDTC). The formed hydrophobic complex is subsequently extracted into the lumen of hollow fiber, whereas Sb(V) is remained in aqueous solutions. The extraction organic phase was injected into TS-FF-AAS for the determination of Sb(III). Total Sb concentration was determined after reduction of Sb(V) to Sb(III) in the presence of l-cysteine and the extraction procedure mentioned above. Sb(V) was calculated by subtracting of Sb(III) from the total Sb. DDTC was used as complexing reagent. 1-Octanol was immobilized in the pores of the polypropylene hollow fiber as liquid membrane and also used as the acceptor solution. Some parameters that influenced extraction and determination were evaluated in detail, such as concentration of sodium diethyldithiocarbamate (DDTC), type of organic solvent, pH of samples, stirring rates, extraction time, as well as interferences. Under optimized conditions, a detection limit of 0.8ngmL -1 and an enrichment factor of 160 were achieved. The relative standard deviation (RSD) was 6.2% for Sb(III) (50ngmL -1, n=5). The proposed method was successfully applied to the speciation of Sb(III) and Sb(V) in environmental and biological samples with satisfactory results. © 2011 Elsevier B.V.


Zeng C.,Yulin Normal College | Hu Y.,Chengdu Textile College | Luo J.,Yulin Normal College
Microchimica Acta | Year: 2012

We have developed a simple and effective method for hollow fiber liquid-phase microextraction of cadmium. It is based on the use of a room temperature ionic liquid (RTIL) and was coupled to thermospray flame furnace AAS. The RTIL was placed in the pores of a polypropylene hollow fiber (acting as a liquid membrane) and also used as the acceptor solution. Ammonium pyrrolidinedithiocarbamate (APDC) was used as the chelating agent. The effects of the concentration of APDC, the pH of samples, stirring rates, extraction time, and potential interferences were optimized to result in a detection limit of 9 ng L -1 and an enrichment factor of 90. The relative standard deviation is 4. 7% (at 0. 5 ng mL -1, for n = 5). The method was successfully applied to the determination of cadmium. © 2011 Springer-Verlag.


A novel method to preconcentrate gold was developed employing a synergistic enhancement of a room temperature ionic liquid combined with hollow fiber liquid phase micro-extraction with flame atomic absorption spectrometry detection. The method is based on the complexation of gold with dithizone. The formed hydrophobic complex was subsequently extracted into the lumen of a hollow fiber. The organic phase was siphoned into FAAS for the determination. A room temperature ionic liquid and dithizone were used the enhancement reagent and chelating reagent, respectively. The addition of a room temperature ionic liquid led to a five-fold improvement in the extraction of gold. The 1-octanol was immobilized in the pores of the polypropylene hollow fiber as the liquid membrane and was also used as the acceptor solution. Some parameters that influenced extraction and determination were evaluated in detail, such as concentrations of the ionic liquid and dithizone, pH of samples, stirring rates, extraction time, and interferences. Under optimized conditions, a detection limit of 0.9 ng mL-1 and an enrichment factor of 130 were achieved. The relative standard deviation (RSD) was 3.7% for Au (40 ng mL-1, n = 5). The proposed method was successfully applied to the determination of gold in certified reference environmental samples and ore samples with satisfactory results. © 2013 Copyright Taylor and Francis Group, LLC.


Zeng C.,Yulin Normal College | Tan H.,Yulin Normal College | Gu Y.,Yulin Normal College | Liang C.,Yulin Normal College
Analytical Methods | Year: 2014

A novel method was developed for the chemical vapor generation (CVG) of lead, cadmium and bismuth based on the enhancement effect of room temperature ionic liquids followed by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) determination. Room temperature ionic liquids (RTILs) and ammonium pyrroldinedithiocarbamate (APDC) were used as enhancement reagents and chelating reagents for the CVG of lead, cadmium and bismuth, respectively. TS-FF-AAS was used for the determination of lead, cadmium and bismuth. The addition of RTILs led to an improvement of 3.5, 3.0 and 4.0 times the CVG efficiencies of Pb, Cd and Bi, respectively. The efficiencies for the CVG of Pb, Cd and Bi in the presence of RTILs and APDC were 55%, 46% and 60%, respectively. Volatile species of Pb, Cd and Bi were effectively generated through reduction of acidified analyte solutions with KBH4 in the presence of 0.02% (m/v) APDC and 0.1% (v/v) 1-butyl-3-methylimidazolium tetrafluoroborate ([C4MIM]BF4). Some parameters that influenced CVG and the subsequent determinations were evaluated in detail, such as the concentrations of RTILs, APDC, HNO3 and KBH4; the flow rates of the carrier gas, lengths of the reaction tube and transfer tube, as well as interferences. Under optimized conditions, the detection limits for Pb, Cd and Bi were 8, 1 and 5 ng mL-1, respectively. Relative standard deviations for five replicate determinations of a standard solution containing 200 ng mL-1 Pb, Cd and Bi were 4.5%, 5.5% and 5.2%, respectively. The proposed method was successfully applied in the determination of Pb, Cd and Bi in certified environmental reference materials with satisfactory results. © the Partner Organisations 2014.


Zeng C.,Yulin Normal College | Kong J.,Yulin Normal College | Zhou N.,Yulin Normal College | Cui R.,Yulin Normal College | Li X.,Yulin Normal College
Analytical Methods | Year: 2013

A new method for the determination of zinc based on the synergetic enhancement effect of room temperature ionic liquids (RTILs) and ammonium pyrrolidine dithiocarbamate (APDC) by chemical vapor generation (CVG) coupled with flame atomic absorption spectrometry (FAAS) was developed. RTILs and APDC were used as synergetic enhancement reagents. The addition of RTILs led to a 3.6 times improvement in the CVG efficiency of zinc. Zinc hydride was effectively generated with a 48% vapor generation efficiency (the CVG efficiency was calculated on the basis of the concentrations of zinc before and after CVG) by mixing the acidified analyte solutions with KBH4 in the presence of 0.02% (m/v) APDC and 0.1% (m/v) 1-butyl-3-methylimidazolium tetrafluoroborate ([C4MIM]BF4). Some parameters that influenced CVG and subsequent determination were evaluated in detail, such as the concentrations of RTILs, APDC, HNO3 and KBH4; flow rates of the carrier gas, lengths of the reaction tube and transfer tube, as well as interference from other elements. A detection of limit of 9 ng mL-1 and a relative standard deviation (RSD) of 5.7% at 400 ng mL-1 Zn(ii) (n = 5) were obtained under optimal experimental conditions. The proposed method was successfully applied to the determination of zinc in real water samples and certified reference samples with satisfactory results. This journal is © 2013 The Royal Society of Chemistry.


Zeng C.,Yulin Normal College | Lin Y.,Yulin Normal College | Zhou N.,Yulin Normal College | Zheng J.,Yulin Normal College | Zhang W.,Yulin Normal College
Journal of Hazardous Materials | Year: 2012

A new method for the speciation of Cr(VI) and Cr(III) based on enhancement effect of room temperature ionic liquids (RTILs) for hollow fiber liquid phase microextraction (HF-LPME) combined with flame atomic absorption spectrometry (FAAS) was developed. Room temperature ionic liquids (RTILs) and diethyldithiocarbamate (DDTC) were used enhancement reagents and chelating reagent, respectively. The addition of room temperature ionic liquids led to 3.5 times improvement in the determination of Cr(VI). In this method, Cr(VI) reacts with DDTC yielding a hydrophobic complex, which is subsequently extracted into the lumen of hollow fiber, whereas Cr(III) is remained in aqueous solutions. The extraction organic phase was injected into FAAS for the determination of Cr(VI). Total Cr concentration was determined after oxidizing Cr(III) to Cr(VI) in the presence of KMnO4 and using the extraction procedure mentioned above. Cr(III) was calculated by subtracting of Cr(VI) from the total Cr. Under optimized conditions, a detection limit of 0.7ngmL-1 and an enrichment factor of 175 were achieved. The relative standard deviation (RSD) was 4.9% for Cr(VI) (40ngmL-1, n=5). The proposed method was successfully applied to the speciation of chromium in natural water samples with satisfactory results. © 2012 Elsevier B.V.


Tan M.,Yulin Normal College | Liu Y.,Guangxi Normal University | Luo X.,Guangxi Normal University | Li D.,Yulin Normal College
Advanced Materials Research | Year: 2012

The total alkaloids (TAE) were obtained from the fruits of Evodia rutaecarpa (Juss.) Benth. The antioxidant activities of TAE towards the inhibitory effect on 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) free radical, total antioxidant capacity, and inhibition on lipid peroxidation were investigated. TAE was found that the total antioxidant capacity and inhibitory lipid peroxidation are superior to synthetic antioxidant 2, 6-di-ter-butyl-4- methylphenol (BHT), but scavenging activity on DPPH radical is lower than that of BHT at the same condition.


Li D.Q.,Yulin Normal College | Tan M.X.,Yulin Normal College | Jie L.,Yulin Normal College
Advanced Materials Research | Year: 2012

Salicylaldehyde azine (SA) were synthesized with salicylaldehyde and hydrazine hydrate as a raw material. The crystal structure was characterized by X-ray diffraction, as well as the total antioxidant capacity and antibacterial activities against Staphylococcus aureus and Escherichia coli were investigated. It was found that SA exhibited significant antibacterial activities and total antioxidant capacity.


Zeng C.,Yulin Normal College | Xu X.,Yulin Normal College | Zhou N.,Yulin Normal College | Lin Y.,Yulin Normal College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

A new method based on enhancement effect of room temperature ionic liquids for cloud point extraction trace amounts of nickel combined with UV-vis spectrophotometric determination was developed. Room temperature ionic liquids (RTILs) and diethyldithiocarbamate (DDTC) were used enhancement reagent and chelating reagent, respectively. The addition of room temperature ionic liquids leads to 3.0 times improvement in the determination of nickel. The nonionic surfactant Triton X-100 was used as the extractant. When the temperature of the system was higher than the cloud point of Triton X-100, Ni-DTC complex was extracted into Triton X-100 and separation of the analyte from the matrix was achieved. Some parameters that influenced cloud point extraction and subsequent determination were evaluated in detail, such as the concentrations of RTILs, DDTC and Triton X-100; pH of sample solution, as well as interferences. Under optimized conditions, an enrichment factor of 72 could be obtained, and the detection limit (LOD) for Ni was 0.5 ng mL -1. Relative standard deviations for five replicate determinations of the standard solution containing 50 ng mL -1 Ni was 3.9%. The proposed method was successfully applied to the determination of nickel in certified reference materials with satisfactory results. © 2012 Elsevier B.V. All rights reserved.


A new method based on chemical vapor generation (CVG) coupled with flame atomic absorption spectrometry (FAAS) was developed for the determination of iron, cobalt and nickel in environmental and biological samples. Room temperature ionic liquids (RTIL) combined with ammonium pyrroldinedithiocarbamate (APDC) were used to synergetically enhance the CVG of iron, cobalt and nickel. The addition of RTIL leads to 2.5, 3.2, 3.0 times improvement in the CVG efficiencies of Fe, Co and Ni, respectively. The efficiencies for the CVG of Fe, Co and Ni in the presence of RTIL and APDC were 42%, 61% and 54%, respectively. Volatile species of iron, cobalt and nickel were effectively generated through reduction of acidified analyte solutions with KBH 4 in the presence of 0.02% or 0.01% (m/v) APDC and 0.1% or 0.2% (m/v) 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4MIM]PF 6). Some parameters that influenced CVG and subsequent determination were evaluated in detail, such as the concentrations of RTIL, APDC, nitric acid (HNO 3) and KBH 4; flow rates of carrier gas, lengths of reaction tube and transfer tube, as well as interferences. Under optimized conditions, the detection limits (LODs) for Fe, Co and Ni were 18, 14 and 11 ng mL -1, respectively. Relative standard deviations for five replicate determinations of the standard solution containing 500 ng mL -1 Fe, Co and Ni were 5.3%, 4.6% and 4.3%, respectively. The proposed method was successfully applied to the determination of iron, cobalt and nickel in certified environmental and biological reference materials with satisfactory results. © 2012 The Royal Society of Chemistry.

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