Sun H.H.,Marine Chemical Research Institute |
Mo X.M.,Qingdao Women and Children Hospital |
Qian Y.M.,Marine Chemical Research Institute
Advanced Materials Research | Year: 2013
To explore and compare the reliability of the quantitative determination of formaldehyde content of water based coatings, the high performance liquid chromatography (HPLC) after derivatization to 2.4-dinitrophenylhydazone and UV-VIS spectrophotometry were studied, respectively. HPLC was performed on a C18 column with acetonitrile/water (65/35, V/V) as mobile phase at a flow rate of 1.0 mL/min, and analyses was detected using Photodode Array Detector (DAD) at the wavelength of 360 nm. And formaldehyde was determined with spectrophotometry at 435nm. The result showed the standard curve of formaldehyde by the HPLC method was linear in the range of 0.1-5.0 mg/L (R2=0.9998). The detection limit was 0.96mg/kg, recoveries were ranging from 96.2% to 101.3%. The linear range of formaldehyde by the spectrophotometric method was 0.1~5.0 mg/L (R2=0.9995), and the detection limit was 5.93mg/kg, recoveries were ranging from 98.5% to 105.3%. In conclusion, both the two methods can be used for quantitative analysis of formaldehyde in water based coatings, and the major advantages of HPLC are quick, simple and sensitive. © (2013) Trans Tech Publications, Switzerland.
Wang W.,Ocean University of China |
Li R.,Qingdao Women and Children Hospital |
Song T.,Ocean University of China |
Zhang C.,Ocean University of China |
Zhao Y.,Ocean University of China
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2016
In order to study the influence of different substituent groups on the fluorescence properties, a series of bis-Schiff bases (L) with electron-donating groups (salicylaldehyde, o-vanillin, 2,4-dihydroxybenzaldehyde) and electron-drawing group (4-formylbenzoic acid) have been synthesized, and characterized by IR spectrum, NMR, mass spectrum, and fluorescence spectroscopy. The investigation of the fluorescent properties reveals that the fluorescence can be enhanced when the bis-Schiff base ligands with electron-donating groups complex with Zn ion, while other kinds of metal complexes with these ligands do not show any enhancement, whereas no fluorescence enhancement can be observed when the ligand with electron-drawing group complexes with all different types of metal ions. In addition, as for the ligands with electron-donating groups detecting zinc ion, the fluorescence intensity is linear correlated with the concentration of zinc ion. Therefore, the study indicates that the ligands with electron-donating groups can be used as Zn ion fluorescent sensor. © 2016 Elsevier B.V. All rights reserved.
Hui N.,Qingdao University of Science and Technology |
Wang S.,Qingdao University of Science and Technology |
Xie H.,Qingdao Women and Children Hospital |
Xu S.,Qingdao University of Science and Technology |
And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2015
A facile two-step electrochemical strategy was reported to synthesize nanocomposite of reduced graphene oxide (RGO) doped conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) decorated with nickel nanoparticles (NiNPs) onto a glassy carbon electrode (GCE). Pure graphene oxide (GO) doped PEDOT composite was firstly electropolymerized onto the GCE through cyclic voltammetry, followed by electrochemical reduction in a solution containing nickel cations at a constant potential of -0.9 V. During the electrochemical reduction process, GO doped in the PEDOT composite would be reduced to a more conductive form of RGO, and at the same time, nickel cations could be reduced to form NiNPs and loaded on the composite surface. The prepared nanocomposite (NiNPs/PEDOT/RGO) modified electrode showed outstanding electrocatalytic activity toward the oxidation of glucose in alkaline media, and it could be developed into a nonenzymatic glucose sensor. Under optimum conditions, the glucose sensor exhibited a linear range from 1.0 μM to 5.1 mM and a detection limit of 0.8 μM (S/N = 3), associated with excellent stability, high reproducibility and favorable selectivity against common interferents. Furthermore, the nonenzymatic sensor was also successfully applied to the detection of glucose in human serum samples, showing promising potential in the clinical application. © 2015 Elsevier B.V. All rights reserved.
Mo X.-M.,Ocean University of China |
Chen Z.-F.,Qingdao Women and Children Hospital |
Qi X.,Ocean University of China |
Li Y.-T.,Ocean University of China |
Li J.,Ocean University of China
Bioinorganic Chemistry and Applications | Year: 2012
Vanadium compounds were studied during recent years to be considered as a representative of a new class of nonplatinum metal anticancer agents in combination to its low toxicity. Here, we found a vanadium compound Van-7 as an inhibitor of Topo I other than Topo II using topoisomerase-mediated supercoiled DNA relaxation assay. Agarose gel electrophoresis and comet assay showed that Van-7 treatment did not produce cleavable complexes like HCPT, thereby suggesting that Topo I inhibition occurred upstream of the relegation step. Further studies revealed that Van-7 inhibited Topo I DNA binding involved in its intercalating DNA. Van-7 did not affect the catalytic activity of DNase I even up to100 μM. Van-7 significantly suppressed the growth of cancer cell lines with IC 50 at nanomolar concentrations and arrested cell cycle of A549 cells at G2/M phase. All these results indicate that Van-7 is a potential selective Topo I inhibitor with anticancer activities as a kind of Topo I suppressor, not Topo I poison. © 2012 Xiao-mei Mo et al.
Meng L.,Ocean University of China |
Sun S.,Ocean University of China |
Li R.,Qingdao Women and Children Hospital |
Shen Z.,Ocean University of China |
And 2 more authors.
Carbohydrate Polymers | Year: 2014
Extracellular polysaccharide (EPS) and intracellular polysaccharide (IPS) were produced in a mycelial liquid culture of the Hirsutella sp. liquid fermentation. The polysaccharides were precipitated with 50% ethanol (EPS-1, IPS-1), 65% ethanol (EPS-2, IPS-2) and 80% ethanol (EPS-3, IPS-3). The polysaccharide fragments precipitated in lower ethanol percentages had a lower neutral sugar content and a larger molecular weight. EPS-1, EPS-2, IPS-1 and IPS-2 were composed of glucose (Glu), galactose (Gal) and mannose (Man). Galactose was not detected in EPS-3 and IPS-3. Evaluated by the 1/IC50 values of hydroxyl radical scavenging activity, the polysaccharides with higher protein content, lower neutral sugar content and molecular weight about 10-20 kDa were found to have better radical scavenging activity. Significant correlations demonstrated that the antioxidant effect of the polysaccharides was influenced by monosaccharide composition (mannose, r = 0.942; glucose, r = -0.905).