Biomedical subjects

Liu Jiaming

Publications and source records attributed to Liu Jiaming.

3 recordsLinked to original sources

PubMed2005

Determination of trace silver by solid substrate-room temperature phosphorescence quenching method based on double catalytic system of meta-nitrophenyfluorone-polyoxyethylene-chromium-potassium bromate-beta-cyclodextrin.

A new solid substrate-room temperature phosphorescence (SS-RTP) quenching method for the determination of trace silver has been established. It is based on the fact that when using Mg(2+) as ion perturber and beta-CD as surfactant, the system of meta-nitrophenyfluorone (R)-polyoxyethylene-Cr(III) can emit strong and stable room temperature phosphorescence signal on filter paper whose surface is modified by polyvinyl alcohol (PVA)-H(3)BO(3)-NaOH. Ag(I) can catalyze KBrO(3) oxidizing R-PEO-Cr(III) system which causes the quenching of SS-RTP. The reducing value of phosphorescence intensity (DeltaI(p)) is directly proportional to the concentration of Ag(I) in the range of 3.2-160 ag spot(-1) (corresponding concentration: 2.43 fg ml(-1), the sample volume: 0.40 microl spot(-1)) with a detection limit (LD) of 0.97 ag spot(-1). The regression equation of working curve can be expressed as DeltaI(p)=13.92+0.3089m(Ag)+ (ag spot(-1)) (r=0.9983, n=6). This method has many advantages, such as a wide linear dynamic range, high sensitivity, good repeatability and selectivity. It has been applied to the determination of trace silver in real samples with satisfactory results. What is more, the mechanism of SS-RTP quenching method based on Ag(I) catalyzing KBrO(3) oxidizing meta-nitrophenyfluorone has also been discussed.

Catalysis↗

PubMed2005

Determination of trace silver by solid substrate room temperature phosphorescence quenching method based on lead carboxymethyl cellulose particles (Pb(CMC)2) containing luminescent salicyl fluorenes molecules.

Luminescent particles of lead carboxymethyl cellulose (Pb(CMC)2) containing salicyl fluorones (THBF), Pb(CMC)2-THBF were synthesized by the sol-gel method, using sodium carboxymethyl cellulose (NaCMC) as precursor and Pb2+ as precipitant. Pb(CMC)2-THBF can emit the intense and stable solid substrate room temperature phosphorescence (SS-RTP) on filter paper. And EDTA can chelate Pb2+ in Pb(CMC)2-THBF, causing it to decompose into aqueous soluble components PbY2-, CMC- and THBF, which can react with Ag+ to form Ag(CMC)2-THBF, causing the decrease of phosphorescence intensity. Based on the facts above, a new method for the determination of trace silver by SS-RTP quenching method was established. The linear range of this method is 8.0-40.0 fg spot(-1) (20.0-100.0 pg ml(-1)), with a detection limit (LD) of 2.2 fg spot(-1) (corresponding to a concentration range of 5.5 x 10(-13) g ml(-1)), and the regression equation of working curve is DeltaI(p) = 12.56 + 0.5527C(Ag+) (fg spot(-1), 0.4 microl spot(-1)), n = 8, r = 0.9992. This method has been applied to the determination of trace silver in human hair and tea sample with satisfactory results. The mechanism of SS-RTP emission is also discussed.

Carboxymethylcellulose Sodium↗

PubMed2003

Determination of trace tin by solid substrate-room temperature phosphorimetry using sodium dodecyl sulfate as sensitizer.

The effects of different surfactants on solid substrate-room temperature phosphorescence (SS-RTP) properties of Sn(4+)-morin systems were investigated. It was found that the SS-RTP intensity of luminescence system was increased greatly in presence of sodium dodecyl sulfate (SDS). A new highly sensitive method for the determination of trace tin has been proposed based on sensitization of SDS on SS-RTP intensity of morin-tin system on the filter paper substrate. The linear dynamic range of this method is 8.0-112 ag per spot (with the volume of 0.4 microl per spot) with a detection limit of 4.0 ag per spot, and the regression equation is DeltaIp=199.7+3.456m(Sn(IV)) (ag per spot), with the correlation coefficient r=0.9998 (n=7). This simple, rapid and reproducible method has been applied to determine the amount of tin in real samples with satisfactory results.

Luminescence↗