Capture of cervical exfoliative cells on a glass slide coated by 3-glycidyloxypropyl trimethoxysilane and poly-L-lysine.

A new modification method for glass slides was developed and applied to make ThinPrep Pap smears, in order to increase the adhesion ability of cervical exfoliative cells. 3-glycidyloxypropyl trimethoxysilane (GOPS) was coated on the glass slides firstly on the slides, then poly-L-lysine (PLL) was covalently modified onto the above epoxy-terminated slides to form GOPS-PLL double decorated slides. The modified slides were characterized using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The cell adhesion ability effect was tested and compared with traditional PLL coated slides by fixing the cervical exfoliative cells on the double adorned slides. The control test was conducted by the bare glass slides unmodified. The cell morphology of cervical exfoliative cells adhered on different slides was observed under the microscope after Papanicolaou staining. The number of cervical exfoliative cells on the unmodified slides, PLL coated slides and GOPS-PLL coated slides was 1030±300, 3283±226 and 4119±280 (n=12), respectively. The data among the three different modification methods showed significant differences (one-way analysis of variance, ANOVA test, P<0.05). The cell capturing effect of the GOPS-PLL slide was the best among the three different modified slides. In addition, the GOPS-PLL slide could enhance the uniformity of the adhered cells and be widely applied to the ThinPrep system for cervical carcinoma screening to increase the accuracy rate of diagnosis.

[Determination of metacycline in mixture sample by synchronous-derivative fluorimetry].

A new synchronous-derivative fluorimetric method for the determination of metacycline (MTC) in the presence of oxytetracycline (OTC) is proposed. The degradation products of MTC in 0.1 mol x L(-1) NaOH are strongly fluorescent. The addition of cetyltrimethylammonium bromide (CTMAB) enhances the fluorescence intensity 2-fold. The synchronous fluorescence spectra of MTC and OTC degradation products do not interfere with each other under the condition that deltalambda = 100 nm. MTC can be determined in the presence of OTC in the range of OTC+MTC ratio of 1+116-1+1. The recoveries of MTC in the mixture sample are in the range of 94%-102%.

[Simultaneous determination of germanium and some major ash forming elements in lignites using a dual-view ICP-OES].

In this article, an ICP-OES method of simultaneous determination germanium and some major ash forming elements especially for Fe, Al, Ca, Mg, K, Na, Ti in lignites is described. An ICP-OES instrument equipped with a dual-view plasma torch and a simultaneous detector was used. This technology allows the simultaneous determination of trace elements and major components in the axial view along with in the radial view. The moderate operation condition of the instrument and analytical wavelength lack of interference from elements in the sample matrix was selected, the spectral background was automaticly eliminated. The obtained coal ashes were dissolved in mixtures of nitric acid, hydrofluoric acid and perchloric acid after coal samples were cinerated. The analytical results were in good agreement with those provided by national standard methods. The detection limit of the instrument is ranged between 0.00039-0.10 microg. x mL(-1), the precision of the method is in the range of 0.79%-2.84%, the average recovery of samples is 92.38%, the proposed method is well suitable for the determination germanium and some major ash forming elements in lignites.

[Determination of enoxacin in urine by synchronous fluorimetry].

The effect of metal ions on uhe fluorescence spectra of enoxacin was studied in detail. It has been found that aluminum can enhance the fluorescence intensity of enoxacin remarkably in the buffer solution of NaH2 PO4-Na2B4O7 with pH 6.3. A new method using synchronous fluorimetry has been developed for the determination of enoxacin in human urine. The synchronous fluorescence intensity of Al/ENX system is linearly proportional to the concentration of ENX in the concentration range of 0.04-1.0 microg x mL(-1). The detection limit, calculated according to IUPAC recommendations, was 0.018 microg x mL(-1). The precision of the method was established by repeated assays (n = 12) using 0.4 microg x mL(-1) solution of ENX, and the relative standard deviation was 3.1%. The method was satisfactorily applied to the determination of enoxacin in human urine samples. The recovery was within the range of 95%-105%.

[Determination of iron(III) in Chinese herbal medicine and tea based on fluorescence quenching of 2,4-dichro-phenylfluorone].

A new spectrofluorimetric method for the determination of trace amount of Fe(III) has been developed. This method is based on the fluorescence quenching of 2,4-dichro-phenylfluorone due to the formation of complex Fe(III)-DCIPF. In pH 5.2-5.9 buffer solution, Fe (III) and DCIPF react on each other to form a red complex. Its composition was established by method of continuous variations and molar-ratio as Fe(III): DCIPF = 1:4, the excitation and emission wavelengths were found to be 282 and 560 nm, respectively. There is a linear relationship in the range 4-24 ng x mL(-1) for Fe(III). This method is simple and rapid, and has been applied to the determination of trace iron in Chinese herbal medicine and tea samples with satisfactory results.