Biomedical subjects

Zhi-xia Zhuang

Publications and source records attributed to Zhi-xia Zhuang.

7 recordsLinked to original sources

PubMed2006

[Preparation and characterization of chitosan membrane for solid phase microextraction technique].

Chitosan is a kind of natural polymers containing plenty of amido and hydoxy. The chitosan membrane is tough, and since the partition coefficient of chlorophyll between chitosan membrance and water is as high as 9,090, the chitosan membrane may beeasily manufactured as solid-phase microextraction membrane for the analysis of chlorophyll. The system may reach a complete equilibrium in 80 min. Then the membrane can be desorbed completely in 30 min in 5% NaOH with ultrasonic. Both IR and XRD indicated that hydrogen bonds between the molecules of chitosan were weakened and amido and hydoxy were considered as the keys during the process of extracting chlorophyll.

Chitosan↗

PubMed2005

[Fabrication of relative humidity optical fiber sensor based on nafion-crystal violet sensing film].

With two kinds of sensing methods for relative humidity based on fluorescence and visible absorption respectively, crystal violet was opted as the molecule probe for humidity. The optical chemical sensing film for humidity was prepared when crystal violet was embedded in the Nafion gel. The relative humidity sensor was fabricated after the sensing film had been coupled with other components, such as optical fiber and detector, which possessed short response time ( < 2 min), high sensitivity (< or = 5% RH), wide dynamic range (30%-100%) and good reversibility (RSD < or = 2.6%) for relative humidity at 640 nm wavelength.

Air↗

PubMed2005

[Study on Hg2+ distribution and speciation in different tissues of rats].

Mercury is one of the important pollutants that threaten people health greatly in environment. The purpose of this paper was to determine mercury distribution and mercury binding proteins in different tissues of rat fed orally with mercuric chloride by ICP-MS and SEC-UV-ICP-MS. The result showed that liver and kidney induced large amount of metallothioneins that was found to bind to mercury, copper and zinc after mercury intake in stomach and intestines. The metallothioneins induced may be prior to combine the mercury so that it would decrease mercury binding with the other proteins that would disable their normal function.

Administration, Oral↗

PubMed2005

[Determination of mercury in Chinese medicinal material and biological samples using pyrolysis atomic absorption spectrometry].

In this paper a rapid and simple method using pyrolysis coupled with atomic absorption spectrometry for the analysis of total mercury in Chinese medicinal material and biological samples is presented. No sample digestion was needed and this greatly simplifies the analytical procedure and minimizes potential sources of contamination. Under optimum conditions, the reproducibility of the method was 2.1% for peak area and 9.1% for peak height. The detection limit (3sigma) was 6.3 ng x g(-1), and the recovery was within the range of 95%-105%. Several standard reference materials were analyzed and the results were obtained with satisfaction. The performance of the method was compared with inductively coupled plasma-mass spectrometry (ICP-MS), and excellent agreements were observed between these two methods.

Animals↗

PubMed2003

[Preparation and characterization of Radix Salvia reference material for heavy metals under GAP control].

OBJECTIVE: To prepare and characterize the heavy metal reference material of radix salvia planted in Zhongjiang, Sichuan province under the good agricultural procedure (GAP). METHOD: After being prepared, the reference material was digested with 65% HNO3 and H2O2 by microwave-assisted oven systems, and the heavy metals in Radix salvia reference material were accurately determined by inductively coupled plasma mass spectrometry (ICP-MS). RESULT: The measuring method was validated by running certificated reference materials, including bush twigs and leaves (GBW07602) and tea twigs and leaves (GBW07605) under the same conditions. The recoveries of the elements mostly ranged from 90% to 110%, and the RSD was within 5%. The measurement of radix salvia reference material was carried out by different laboratories with ICP-MS and by several time intervals in one year for the stability. The results showed that the concentration of the heavy metals provided were accurate and the reference material was stable. CONCLUSION: The reference material is suitable to be the criterions of heavy metals for radix salvia in the qualities controlling, and is also suitable to be the criterion of poisonous heavy metals of other herbs in the administration of GAP.

Agriculture↗

PubMed2002

[Speciation of 9 trace elements in a traditional Chinese medicine long dan cao by flow injection-inductively coupled plasma mass spectrometry with a focused microwave assisted extraction system].

A method based on focused microwave extraction for leaching 9 trace elements in traditional Chinese medicine Long Dan Cao was introduced. An online C18 enrichment-separation system and an HP4500 ICP mass spectrometer with a flow injection system was established for the separation and determination of inorganic speciation and organic speciation of the selected elements. Orthogonal design was applied for the optimization of microwave leaching conditions. The results showed that the temperature was the major factor for the leaching recoveries.

Calcium↗

PubMed2002

[pH sensors based on rubbery ormosils preparation and their spectrum studies].

A new type of methyl substituted ormosils as a matrix for bromophenol blue (BPhB) and bromocresol green (BCG) is described. The new ormosils combine features of classical TEOS sol-gel material such as solvability in organic solvent and those of sol-gel glasses such as transparent and a porous structure, the ormosils also make a good mechanical stability. The influence of the conditions during the polymerisation process on the photochemical properties of BPhB and BCG has been studied. This sol-gel material was wed to immobilize pH-sensitive absorption dyes, bromothymol blue and bromocresol green, to prepare pH sensing films. The several aspects of the sensing films, including the leaching of the dye from gel, response time to different pH buffer solution, absorption spectra and the improvement of the immobilization of the dyes to filmo, were also discussed.

English Abstract↗