title: [A study on decreasing the instrument detection limit of atomic fluorescence spectrometry (AFS-930) for Hg].
abstract: In the present study, the detection limit of atomic fluorescence spectrometry (AFS-930) was decreased to 2 ng x L(-1) (n=6) based on several optimizing modifications, including that the sub-high voltage of photomultiplier tube and the current of hollow-cathode lamp were elevated to 280 V and to 30 mA, respectively, and the height of atomization cell was set as 10 mm; In addition, the concentration of KBH4 was decreased to 0.5% (KOH 0.2%). With the optimized parameters, a good standard curve of Hg concentration versus intensity of fluorescence (If) could been obtained readily, after that, a 4-ng x L(-1)-Hg water samples was measured accurately with a little relative standard deviation (RSD) of <5%, while for approximately 2-ng x L(-1)-Hg waters the RSD varied within a wide range of 10.9%-27.2%, likely due to the absorption of Hg by polyethylene vessels used in this study and/or due to the contamination by analysis grade reagents used in this study. By using low-absorption polytetrafluoroethylene (PTFE) materials and the guaranteed reagents, the instrument detection limit was further decreased to 1 ng x L(-1) (n=10).
authors: Soil and Environment Bioremediation Research Center, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. xbyin@ustc.edu.cn
authors: Xue-bin
authors: XB
authors: Yin
authors: Xiao-qi
authors: XQ
authors: Lu
authors: Chun-xia
authors: CX
authors: Yao
authors: Jing
authors: J
authors: Song
authors: Wei
authors: W
authors: Qian
authors: Yong-ming
authors: YM
authors: Luo
authors: You-qing
authors: YQ
authors: Liang
authors: Li-guang
authors: LG
authors: Sun
mesh_terms: D001894:Borohydrides / Q000737:chemistry; D002138:Calibration; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis; D020959:Polyethylene / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D014867:Water / Q000737:chemistry
chemical_list: D001894:Borohydrides; D014867:Water; C028371:potassium borohydride; D020959:Polyethylene; D008628:Mercury