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Liu C.,Fuzhou University | Luo F.,Fujian Research Institute of Metric Science | Chen D.,Fujian Research Institute of Metric Science | Qiu B.,Fuzhou University | And 3 more authors.
Talanta | Year: 2014

A simple and rapid fluorescence method has been developed for the determination of acrylamide in heat-processed food samples. In the determination, acrylamide is degraded through Hofmann reaction to generate vinyl amine, and pyrrolinone is produced when the vinyl amine reacts with fluorescamine, resulting in a strong fluorescence emission at 480 nm. Hofmann reaction is a key step for the fluorescence determination of acrylaminde, and the reaction conditions are investigated and optimized. Under the optimal conditions, the fluorescence intensity increases with the increase of acrylamide concentrations. The linear range between the fluorescence intensity and the square-root of acrylamide concentrations is from 0.05 μg mL-1 to 20 μg mL-1 with the correlation coefficient R2=0.9935. The detection limit is 0.015 μg mL-1 and the recovery for food samples is from 66.0% to 110.6%. In comparison with Specification of Entry&Exit Inspection and Quarantine Bureau of The Peoples Republic of China (SN/T 2281-2009), the method showed comparable results and demonstrated the accuracy of the method. © 2014 Elsevier B.V. All rights reserved.

Du Y.,Fuzhou University | Chen M.,Fuzhou University | Zhang Y.,Fuzhou University | Luo F.,Fujian Research Institute of Metric Science | And 3 more authors.
Talanta | Year: 2013

A new method for determination of iron(III) has been developed using a kind of rhodamine B derivative fluorescent probe, rhodamine amide (RHA), in acidic HAc-NaAc buffer solution. In this approach, the heavy atom effect of I 3 - was applied to quench the fluorescence of RHA. When iron(III) and KI coexisted in HAc-NaAc buffer solution, iron(III) reacted with the excess KI to produce I3 - that quenched the fluorescence of RHA through the formation of a non-fluorescence compound. The results showed that the fluorescence intensity decrease of RHA presented a good linear relationship with the iron(III) concentrations in the range from 0.5 to 5.0 μmol L-1 with the correlation coefficient of 0.9970, and the detection limit was 0.3 μmol L-1 iron(III). The approach was applied to determination of iron(III) in water samples, and the recovery was found to be from 80.7% to 100. 8%. © 2012 Elsevier B.V. All rights reserved.

Zhang M.,Zhangzhou Normal University | Huang J.,Zhangzhou Normal University | Yu P.,Fujian Research Institute of Metric Science | Chen X.,Xiamen University
Talanta | Year: 2010

A novel protein molecularly imprinted membrane (PMIM) was synthesized on the surface of multiwalled carbon nanotubes (MWNTs) through a surface molecular imprinting technique by using bovine serum albumin (BSA) as the template molecule, acrylamide (AAm) as the functional monomer, N,N′-methylenebisacrylamide (NNMBA) as the cross-linker and ammonium persulphate [(NH4)2S2O8] as the initiator. The amounts of raw materials were optimized in this paper and the suitable amount is 0.1 g of CNTs, 0.02 g of BSA, 0.24 g of AAm, 0.1 g of MBA and 0.025 mg of (NH4)2S2O8. The selective recognition ability of PMIM/MWNTs was evaluated using adsorption experiments. Maximum adsorption capacity was 5.53 μg/mg PMIM/MWNTs and a saturation value was achieved at a BSA concentration of 0.2 mg/mL. The selectivity adsorption experiments showed that the PMIM/MWNTs also had higher adsorption capacities for BSA than for such molecules, as HSA, HB, pepsin and HRP. The PMIM/MWNTs displayed a 2.6-fold increase in affinity to BSA compared to the nPMIM/MWNTs. The PMIM/MWNTs, on the other hand, did not exhibit any significant change in affinity to other molecules compared to the nPMIM/MWNTs. In the experiment, the characteristics of the PMIM/MWNTs were analyzed using infrared spectroscopy and their configurations were observed using scanning electron microscopy. © 2009 Elsevier B.V. All rights reserved.

Qu Y.,Fuzhou University | Qu Y.,Fujian Agriculture and forestry University | Liu C.,Fuzhou University | Luo F.,Fujian Research Institute of Metric Science | And 2 more authors.
Journal of Separation Science | Year: 2013

We developed a solid-phase microextraction coupled to GC with electron-capture detection method for the detection of acrylamide in food samples. Single-walled carbon nanotubes and polypyrrole were electropolymerized onto a stainless-steel wire as a coating, which possessed a homogeneous, porous, and wrinkled surface, chemical and mechanical stability, long lifespan (over 300 extractions), and good extraction efficiency for acrylamide. The linearity range between the signal intensity and the acrylamide concentration was found to be in the range 0.001-1 μg/mL, and the coefficient of determination was 0.9985. The LOD, defined as three times the baseline noise, was 0.26 ng/mL. The reproducibility for each single fiber (n = 6) and the fiber-to-fiber (n = 5) repeatability prepared in the same batch were less than 4.1 and 11.2%, respectively. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhou T.,Xiamen University | Huang Y.,Xiamen University | Li W.,Xiamen University | Cai Z.,Xiamen University | And 3 more authors.
Nanoscale | Year: 2012

A facile approach was developed to prepare positively charged and red-emitting lysozyme-stabilized Ag nanoclusters (Lys-AgNCs) using NaBH 4 as a reducing agent at room temperature. The Lys-AgNCs can be applied in the highly selective detection of Hg 2+. This journal is © 2012 The Royal Society of Chemistry.

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