求助文献2篇，谢谢！

【序号】：1

【作者】：Kazuhiro Kimata et al.

【题名】：Chromatographic Characterization of Silica C18 Packing Materials. Correlation between a Preparation Method and Retention Behavior of Stationary Phase

【期刊】：Journal of chromatographic Science

【年、卷、期、起止页码】：1989, 27, 721-728

【全文链接】：http://chromsci.oxfordjournals.org/content/27/12/721.short

【序号】：2

【作者】：Xue Li et al.

【题名】：Use of Polyetheretherketone as a Material for Solid Phase Extraction of Hydroxylated Metabolites of Polycyclic Aromatic Hydrocarbons in Human Urine

【期刊】：Anal. Chem.

【年、卷、期、起止页码】2013, 85 (7), pp 3526–3531

【全文链接】：http://pubs.acs.org/doi/abs/10.1021/ac303402s