University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Qin Han Jin

Abbrev:
Jin, Q.H.
Other Names:
Qinhan Jin
Address:
Department of Chemistry, Jilin University, Changchun 130023, China
Phone:
NA
Fax:
+86-431-8499805

Citations 8

"Application Of Microwave Techniques In Analytical Chemistry"
Trends Anal. Chem. 1999 Volume 18, Issue 7 Pages 479-484
Qinhan Jin, Feng Liang, Hanqi Zhang, Liwei Zhao, Yanfu Huan and Daqian Song

Abstract: The latest developments in the application of microwave techniques to analytical chemistry are reviewed. Some applications of microwave techniques to sample digestion, solvent extraction, sample drying, the measurement of moisture, analyte desorption and adsorption, sample clean-up, chromogenic reaction, speciation and nebulization of analytical samples are presented. Of 1999 Elsevier Science B.V. All rights reserved.
Speciation

"Semi-online Preconcentration Of Cd, Mn And Pb On Activated Carbon For GFASS"
Talanta 2003 Volume 59, Issue 5 Pages 989-997
Su Xingguang, Wang Meijia, Zhang Yihua, Zhang Jiahua, Zhang Hanqi and Jin Qinhan

Abstract: This paper presents a method whereby trace elements in NH4Cl-NH3 medium are adsorbed on activated carbon in a micro-flow-injection (FI) semi-online sorbent extraction pre-concentration system and then determined by graphite furnace atomic absorption spectrometry (GFAAS). The analytical performance of the proposed method for determining Cd, Mn and Pb was studied. A microcolumn packed with activated carbon was used as a pre-concentration column (PCC). The metals to be determined were pre-concentrated onto the column for 60 s and then rinsed with 0.02% (v/v) HNO3 and eluted with 30 µl of 2 mol L-1 HNO3. Compared with the direct injection of 30 µl of aqueous sample solution, enrichment factor of 32, 26, and 21 and detection limits (3s) of 0.4, 4.7, and 7.5 ng L-1 for Cd, Mn and Pb, respectively, were obtained with 60 s sample loading at 3.0 mL min-1 for sorbent extraction, 30 µl of eluate injection, and peak area measurement. The precisions (RSD, n=6) were 2.8% at the 0.05 µg L-1 level for Cd, 3.0% at the 0.3 µg L-1 level for Mn, and 3.1% at the 0.5 µg L-1 level for Pb. The experimental results indicate that the procedure can eliminate the fundamental interferences caused by alkali and alkaline earth metals and the application of it to the determination of Cd, Mn and Pb in some water samples is successful.

"Flow Injection Online Column Preconcentration For Low Powered Microwave Plasma Torch Atomic-emission Spectrometry"
Talanta 1996 Volume 43, Issue 4 Pages 535-544
Ye Dongmei, Zhang Hanqi and Jin Qinhan*

Abstract: Sample solutions in 0.05 M NH4Cl/NH3 buffer of pH 9 were pumped at 1.7 ml/min through a column (3.5 cm x 3 mm i.d.) packed two-thirds full with a thiol resin (type 190) similar to Duolite ES-465. After 1 min, the adsorbed cations were eluted in the reverse direction with 1 M HCl (1.3 ml/min) into a desolvating system of a heated glass tube, a water-cooled condenser and a wash vessel of concentrated H2SO4. The concentration solution was then transported into a pneumatic concentric nebulizer with Ar as carrier gas. The microwave plasma torch conditions were optimized for the detection of Cd(II), Cu(II), Mn(II) and Zn(II). Enrichment factors of 4-5 were achieved. Calibration graphs were linear for 0.01-20 µg/ml (0.05-20 µg/ml for Mn), with detection limits of 1.8-3.6 ng/ml. For 0.3 µg/ml of Cd(II), Cu(II) and Zn(II) and 1 µg/ml of Mn(II) the RSD were 0.7-1.2% (n = 3). Large amounts of alkali metals, which can interfere with the plasma emission, were eliminated in the pre-concentration step.
Cadmium Copper Manganese Spectrophotometry Interferences Preconcentration

"Flow Injection Semi-online Sorbent Extraction Preconcentration For Graphite Furnace Atomic Absorption Spectrometry"
Microchem. J. 1999 Volume 62, Issue 3 Pages 316-327
Qinhan Jin, Xingguang Su, Feng Liang and Hanqi Zhang

Abstract: A micro-flow injection sorbent extraction pre-concentration system was combined with a graphite furnace atomic absorption spectrometer. The combination results in an integrated system for the determination of trace amounts of heavy metals. Silica bonded with octadecyl functional groups (C-18) was used as a sorbent in a 15 µL conical microcolumn. The metals to be determined were pre-concentrated as diethyl dithiocarbamate chelates onto the column for 60 s and then rinsed with deionized water and eluted with 40 µL of ethanol. Compared with direct injection of 40 µL of aqueous sample solution, enrichment factors of 30, 32, and 29 and detection limits (3s) of 7.8, 12.8, and 3.9 ng/L for cobalt, nickel, and lead, respectively, were obtained with 60-s sample loading at 3.0 mL/min for sorbent extraction, 40 µL of eluate injection, and peak area measurement. The results obtained for trace amounts of cobalt, nickel, and lead in reference materials showed that there were no significant differences between the certified and determined values.
Knotted reactor

"Flow Injection Sample Introduction Into Microwave Plasma"
Microchem. J. 1996 Volume 53, Issue 1 Pages 69-78
Hanqi Zhanga, Dongmei Yea, Jinghong Zhaoa, Jinglei Yua, Ruizhi Mena, Qinhan Jin a, and Defan Dongb

Abstract: The optimization of experimental parameters viz. microwave power, support and carrier gas flow rate, HCl concentration in the sample solution and sample-loop volume was investigated for the detection of fifteen elements (listed) by microwave plasma torch AES (MPT-AES) using a flow injection/pneumatic nebulization (PN) sample introduction system (schematic shown). Under optimized conditions, viz. 60 W microwave power, 650 ml/min carrier gas flow rate, a sample-loop volume of 300 µL and a concentration of 0.05 M HCl in the sample solution the detection limits (DL; 36) obtained for the elements were in the range 5-103 ng/ml. The Dl were almost the same as those obtained with a moderate powered He MPT-AES with an ultrasonic nebulization desolvation system (DS) and are much lower than those obtained by low-powered MPT-AES with PN but without DS as well as moderate-powered Ar CMP with PN-DS. For 0.5-5 µg/nl of added elements RSD were 1.3-5%. Spectral interferences from easily ionizable elements in the matrix were investigated. The method was applied to the analysis of three elements viz. Cu, Ni and Mo in two standard steel samples. Results were in good agreement with certified values.
Copper Nickel Molybdenum Alloy Spectrophotometry Nebulizer Reference material Interferences Optimization

"Recent Advances In Microwave Plasma Torch Atomic-emission Spectrometry"
J. Anal. At. Spectrom. 1998 Volume 13, Issue 5 Pages 377-384
Qinhan Jin, Wenjun Yang, Feng Liang, Hanqi Zhang, Aimin Yu, Yanbo Cao, Jianguang Zhou and Bing Xu

Abstract: The development of an alternative excitation source, the microwave plasma torch (MPT) is historically reviewed. The unique features and shortcomings of the MPT as an excitation source for AES are outlined. To overcome the relatively severe matrix effects, desolvation, flow injection, online preseparation and pre-concentration as well as online standard additions techniques have been adopted. An oxygen-sheathed Ar-MPT has been developed to alleviate the interferences caused by the strong nitrogen-related emission bands and this has also been shown to be valuable in reducing noise levels as well as improving the excitation capability, Some possible future developments are envisioned. (62 References)
Spectrophotometry Review

"A Simple Flow-injection On-line Clean-up System For Microwave Plasma-torch Atomic Emission Spectrometry"
Fresenius J. Anal. Chem. 2001 Volume 370, Issue 8 Pages 1061-1064
Liwei Zhao, Minjing Li, Xiaohang Xie, Daqian Song, Yuan Tian, Lijuan Zhang, Danhong Jin, Hanqi Zhang, Q. Jin

Abstract: A simple flow injection (FI) on-line clean-up system has been developed for microwave plasma-torch atomic emission spectrometry (MPT-AES). A non-selective strongly acidic cation-exchange resin was used to achieve the goal of on-line clean-up. Ag and Zr, which form halogen-complex anions in halide acid media. and Cr. Mo, and P, which exist as acid group anions or acids (neutral) in acidic solution, were determined and the interfering matrix cations were removed on-line. Satisfactory analytical results were obtained from some practical samples by use of this procedure.
Preconcentration Interferences Column

"Studies On The Online Anion Exchange Preconcentration For Graphite Furnace Atomic Absorption Spectrometry"
Gaodeng Xuexiao Huaxue Xuebao 1999 Volume 20, Issue 8 Pages 1189-1193
Su, X.G.;Zhang, H.Q.;Liang, F.;Jin, Q.H.;Bai, S.Z.

Abstract: Flow injection pre-concentration system was introduced into graphite furnace atomic absorption spectrometry in this study. Strongly basic anion exchange fiber was selected as the absorption material, concentrated HCl as complex agent, diluted HCL as eluant. Volume-based elution technique was proposed and applied in this study. Cd, Fe and Zn were determined by the proposed method, The enrichment factors are 19, 17 and 15 (compared with 40 µL sample), the detection limits for the Cd, Pb and:Zn are 1.1, 8.2 and 2.6 ng/L, respectively.