Synthesis of La-Co-O Mixed Oxides via Polyethylene Glycol-Assisted Co-Precipitation Method for Total Oxidation of Benzene.

La-Co-O mixed oxides (LCO) were prepared by co-precipitation method with the presence of polyethylene glycol (PEG) as dispersant. The influence of adding different molecular weight of PEG (0, 2 000, 6 000, 20 000 g·mol-1) on the physicochemical and catalytic properties of La-Co-O mixed oxides for total oxidation of benzene was investigated. The samples were characterized by means of N2 physical adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature-programmed reduction by H2 (H2-TPR), temperature-programmed desorption of O2 (O2-TPD), and X-ray photoelectron spectroscopy (XPS).

Cell microenvironment stimuli-responsive controlled-release delivery systems based on mesoporous silica nanoparticles.

To develop novel tumor cell microenvironment stimuli-responsive smart controlled-release delivery systems is one of the current common interests of materials science and clinical medicine. Meanwhile, mesoporous silica nanoparticles as a promising drug carrier have become the new area of interest in the field of biomedical application in recent years because of their unique characteristics and abilities to efficiently and specifically entrap cargo molecules. This review describes the more recent developments and achievements of mesoporous silica nanoparticles in drug delivery.

[Determination of palladium in automobile exhaust catalysts by FAAS method].

Palladium in automotive exhaust catalyst was determined by flame atomic absorption spectrometry (FAAS). The analytical conditions and the coexisting elements interference were studied. The catalyst was dissolved by the mixture of H2O2 and HCl.

[Determination of protein by synchronous fluorometric method with a new indole homodimeric cyanine as fluorescence probe].

Using a new homodimeric hydrophilic indole dye (Dye-I) as fluorescence probe, a sensitive synchronous spectrofluorometric determination for protein was developed. Characteristics of the fluorescence reaction between DYE-1 and BSA protein were investigated. Effects of the concentration of the hydrophilic dye, pH value of the buffer solution, and ion-intensity of NaCl were also studied and the optimum condition was gained.

[Study of the pH sensitive polymer].

A pH sensitive polymer was prepared by copolymerization of methacrylic acid as monomer, diethylene glycol dimethacrylate as cross-linking reagent, heptane as porogen, and fluorescent dye eosin as indicator. The factors of influence on the preparation, and the character of the pH sensitive polymer for pH were studied. The maximal emission wavelength of eosin was red shifted in the polymer than in solution, the apparent Ka largened, and the dissociation equilibrium of indicator was shifted to acidity direction, because the polarity of polymer diminished.

[Determination of nucleic acids using toluidine blue as a fluorescence probe].

A new fluorimetric method has been developed for the determination of deoxyribonucleic acid (DNA) with toluidine blue (TB) as a fluorescence probe. It is based on the fluorescence quenching of toluidine blue in the presence of DNA. In Tris-HCl buffer solution (pH 8.

[Determination of norfloxacin by flow-injection chemiluminescence].

Sodium dodecylsulfate (SDS) can greatly enhance the emission intensity of the weak chemiluminescence reaction of Ce (IV) with norfloxacin (NFLX) in acid medium. Based on this phenomenon, a simple and rapid new method for the continuous determination of norfloxacin was developed. The calibration graph is linear for 7.

[Direct fluorophotometric and flow-injection fluorophotometric methods for the determination of trace ammonia].

Direct fluorophotometric and flow-injection fluorophotometric methods for trace ammonia measurement involving the fluorescent reaction of ammonia with o-phthaldlaldehyde (OPA) and 2-mercaptoethanol (ME) producing derivant of iso-indol in alkaline solution are described. Triton X-100 was added to improve the stability of the system. The maximum excitation wavelength is 415 nm, while the maximum emission wavelength is 486 nm.

[Study of direct fluorophotometric and flow-injection fluorophotometric methods based on the inhibitory effect for the determination of trace formaldehyde].

Sulfite reacts with o-phthalaldehyde in the presence of ammonium forming the highly fluorescing isoindole-1-sulfonate in neutral or weakly acid solution, and formaldehyde has inhibitory effect on it. Based on this principle, the authors developed the direct fluorophotometric and flow-injection fluorophotometric methods for the determination of trace formaldehyde. The maximum excitation wavelength and the maximum emission wavelength are 320 and 390 nm respectively.

[The study of amphoteric surfacant sensitizing catalytic spectrophotometric determination of Mn (II)].

A new catalytic spectrophotometric method for the determination of trace amount of Mn(II) has been developed. The method is based on the oxidation of thionine by potassium periodate in the presence of nitrilo triaceticacid as an activator and amphoteric surfactant dodecyl dimethylamino acetic acid(DDMAA) as enhancing agent. Dodecye dimethylamino acetic acid (DDMAA) micelles accelerate the reaction and hence increase the sensitivity and selectivity of the determination of Mn(II) compared to reactions taking place in an aqueous medium.