title: High-performance liquid chromatography coupled with mass spectrometry for analysis of ultrasmall palladium nanoparticles.
abstract: Metal nanoparticles (NPs) have recently attracted considerable attention in many areas of research including bioscience, chemistry and material science. Regrettably, most current and past work usually focuses on studies of multi-component NPs mixture where there is a plethora of NPs species co-existing. This work highlights the merits of reverse-phase high-performance liquid chromatography (RP-HPLC) for disclosing the genuine properties of individual palladium nanoparticles (PdNPs) species present in an as-synthesized N,N'-dimethylformamide-stabilized PdNPs product (DMF-PdNPs) which might have been previously hidden or misinterpreted. DMF-PdNPs is successfully separated by RP-HPLC that smaller DMF-PdNPs are approximately eluted first and then follow by the large ones on a C18 column. The separation fractions are further collected and determined their chemical compositions by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results unambiguously reveal that the as-synthesized DMF-PdNPs product is indeed a complex mixture of ultrasmall PdxNPs (x=10-20) stabilized with different numbers of DMF ligands. It is anticipated that the separated fractions afforded by RP-HPLC will offer more accurate determinations of the catalytic, electronic, optical and toxicological properties of metal NPs which might have been previously misinterpreted.
authors.affiliation: Institute of Environmental Science, and School of Chemistry and Chemical Engineering, Shanxi University, 92 Wucheng Road, Taiyuan 030006, China; Biology Institute of Shanxi, 50 Shifan Street, Taiyuan 030006, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Institute of Environmental Science, and School of Chemistry and Chemical Engineering, Shanxi University, 92 Wucheng Road, Taiyuan 030006, China.
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Li
authors.affiliation: Institute of Environmental Science, and School of Chemistry and Chemical Engineering, Shanxi University, 92 Wucheng Road, Taiyuan 030006, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Partner State Key Laboratory of Environmental and Biological Analysis, and Department of Chemistry, Hong Kong Baptist University, 224 Waterloo Road, Kowloon Tong, Hong Kong SAR, China.
authors.forename: Man Chin
authors.initials: MC
authors.lastname: Paau
authors.affiliation: Partner State Key Laboratory of Environmental and Biological Analysis, and Department of Chemistry, Hong Kong Baptist University, 224 Waterloo Road, Kowloon Tong, Hong Kong SAR, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Institute of Environmental Science, and School of Chemistry and Chemical Engineering, Shanxi University, 92 Wucheng Road, Taiyuan 030006, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Gong
authors.affiliation: Institute of Environmental Science, and School of Chemistry and Chemical Engineering, Shanxi University, 92 Wucheng Road, Taiyuan 030006, China.
authors.forename: Shaomin
authors.initials: S
authors.lastname: Shuang
authors.affiliation: Institute of Environmental Science, and School of Chemistry and Chemical Engineering, Shanxi University, 92 Wucheng Road, Taiyuan 030006, China. Electronic address: dc@sxu.edu.cn.
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
authors.affiliation: Biology Institute of Shanxi, 50 Shifan Street, Taiyuan 030006, China.
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Peng
authors.affiliation: Partner State Key Laboratory of Environmental and Biological Analysis, and Department of Chemistry, Hong Kong Baptist University, 224 Waterloo Road, Kowloon Tong, Hong Kong SAR, China. Electronic address: mfchoi@hkbu.edu.hk.
authors.forename: Martin M F
authors.initials: MM
authors.lastname: Choi
keywords: Analytical separation; Chemical composition; Metal nanoparticles