The analysis of cellular lipids and phospholipids has been of continuously increasing research interest due to the importance of these molecules in psychological process.In this work,a mass spectrometry-based method for direct,in situ analysis of lipids in cells was reported.Mammalian cells were directly cultured on ITO-coated glass and then analyzed by matrix-assisted laser desorption ionization-mass spectrometry(MALDI-MS).The matrix application process was achieved by electrospray coating,which produced a homogenous layer of matrix crystal on the sample.The detection results and reproducibility are satisfactory.With this method,a profile of abundant membrane lipids is generated,which is characteristic of cell type.In conclusion,this in situ MALDI-MS cellular lipid analysis method provides a platform for sensitive and robust molecular profiling of mammalian cells.
Chloramphenicol is an antibiotic and one of the potential contaminants in honey.Solid-phase extraction is the key pretreatment procedure for analysis of chloramphenicol in honey.In this work,an on-line pretreatment liquid chromatography-tandem mass spectrometer system for sensitive,reliable and higher throughput analysis was developed.With the methylcellulose-immobilized reversed-phase column,sugars in a honey sample were efficiently removed in 1 min.As a result,the limit of quantitation of chloramphenicol was 20 pg/mL(0.2 μg/kg honey).
Shin-ichi KawanoHong-Yuan HaoYuki HashiJin-Ming Lin
A novel chemiluminescence(CL) performance of CdTe/CdS/ZnS quantum dots(QDs) with periodate(KIO_4) was studied.Effects of concentration and pH on the CL system were investigated.Electron spin resonance(ESR) and the effects of radical scavenger analysis were employed for identification of intermediate species.The CL spectra for this system showed only one maximum emission peak centered around 620 nm,which was similar with photoluminescence(PL) spectra of CdTe/CdS/ZnS QDs.The CL of CdTe/CdS/ZnS QDs was induced by direct chemical oxidation and the possible mechanism could be explained by radiative recombination of injected holes and electrons.This investigation not only provided new sight into the optical characteristics of CdTe/CdS/ZnS QDs,but also broadened their potential optical utilizations.
Yu LiYong-Zan ZhengDing-Kun ZhangHai-Fang LiYuan MaJin-Ming Lin
An analytical method was developed to quantitatively determine selected monohydroxy metabolites of polycyclic aromatic hydrocarbons(PAHs) in human urine. The procedure included enzymatic hydrolysis to cleave the conjugated metabolites, solid-phase microextraction enrichment, and gas chromatography-mass spectrometry analysis. The method proved to be sensitive enough to detect the selected PAH metabolites in human urine.
Libin LiuYueping LuoJunping BiHaifang LiJin-Ming Lin
