Biomedical subjects

Peng Liu

Publications and source records attributed to Peng Liu.

111 records · Page 7Linked to original sources

PubMed2002

[Direct identification of Artemisia argyi, Artemisia dubia and Artemisia lavandulaefolia by FTIR].

OBJECTIVE: To directly and accurately identify Artemisia argyi Levl. et Vant., Artemisia dubia Wall. and Artemisia lavandulaefolia DC. METHODS: Fourier tansform infrared (FTIR) spectrum method was used. RESULT: There were obvious differences among the FTIR spectrums of above-mentioned plants. CONCLUSION: Artemisia argyi Levl. et Vant., Artemisia dubia Wall. and Artemisia lavandulaefolia DC. were directly, fast and accurately identified by FTIR.

Artemisia↗

PubMedDate not supplied

Preparation of poly(propyleneimine) dendrimer immobilized silica gel and its application as novel microcolumn packing for the on-line FI preconcentration and separation of platinum.

A G4.0 poly(propyleneimine) dendrimer immobilized silica gel (PPID-SG) was prepared with a divergent approach from gamma-aminopropyl silica gel (APSG) by repeating the reactions: 1) cyanoethylation of -NH2 and 2) reduction of -CN. Then it was successfully applied as the microcolumn packing for the on-line flow-injection (FI) preconcentration and separation and flame atomic absorption spectrometry (FAAS) determination of Pt. A limit of detection (LOD) of 0.014 microg/mL was obtained when 0.5 microg/mL Pt in chloride acid of PH = 3 was preconcentrated with a sample flow rate of 4.6 mL/min for 60s and the relative standard deviation (RSD) was 2.65%. Coexisting metal ions with concentration of 5.0 mg/mL and anion ions of 20.0 mg/ml have no interference in the determination of Pt. The proposed method was successfully applied to the determination of Pt in nickel alloy and anode slime samples.

Dendrimers↗

PubMedDate not supplied

Interference-free determination of trace levels of gold and palladium in geological and metallurgical samples by flame atomic absorption spectrometry coupled with a flow injection on-line microcolumn preconcentration and separation system.

A simple and highly selective method was developed for the routine determination of trace or ultratrace amounts of gold and palladium in geological and metallurgical samples. The method uses flow injection on-line preconcentration and separation with determination by flame atomic absorption spectrometry. Au and Pd in the sample are adsorbed on a 2-mercaptopyrimidine chemically modified silica gel (MPMSG) packed microcolumn in a 0.50M HCl medium and then eluted with 0.5 or 1.0% thiourea solution. The eluates are introduced into the flame atomic absorption spectrometer directly. With the use of a 0.85 mL microcolumn (about 0.14 g MPMSG packed), the present system tolerated concentrations of common base metal ions up to 25.0 mg/mL and concentrations of anions up to 100.0 mg/mL when Au(III) at 0.100 microg/mL and Pd(II) at 0.200 microg/mL were preconcentrated for 60 s with a sample flow rate of 5.0 mL/min. The limits of detection were 3.1 ng/mL for Au(III) and 6.1 ng/mL for Pd(II) with relative standard deviations of < or = 2.5%. The analytical results obtained by the proposed method for geological and metallurgical samples were in good agreement with the certified values.

Adsorption↗