In this work, a reliable and sensitive method for detecting polybrominated diphenyl ethers （PBDEs） has been developed by the combination of liquid-liquid extraction and gas chromatography-mass spectrometry. PBDEs were extracted from a large volume of water by liquid-liquid extraction and purified by silica gel chromatography. In order to reduce the deviation, dibromobiphenyl was exploited as the internal standard to minimize differences among the injections. The quantification was performed using an external standard. Good linear correlation coefficients （〉0.991） and a wide linearity range （ 1,0- 500.0 ng/L） indicated the steadiness of the proposed method. Moreover, the satisfactory recovery （〉75%） suggested that successful determination of PBDEs in river water had been achieved. Furthermore, the deduction behavior of PBDEs in river water could be inferred according to the results.
Weifei ZhangXuexia LinHai-Fang LiZhihua WangJin-Ming Lin
通过化学键合的方法制备单壁碳纳米管包覆的四氧化三铁(Fe3O4/C N T s)磁性复合纳米粒子。首先用水热法合成磁性Fe3O4纳米粒子,并进行硅烷氨基化处理,羧基化的单壁碳纳米管通过1-(3-二甲基氨基丙基)-3-乙基碳二亚胺(EDC)和N-羟基琥珀酰亚胺(NHS)交联剂反应修饰到Fe3O4纳米颗粒表面。合成的Fe3O4/C N T s复合纳米粒子具有很高的磁响应度和很好的分散能力,是一种很好的分散固相萃取剂。本研究将合成的Fe3O4/C N T s纳米粒子用于分散固相微萃取富集牛奶中的香精添加剂,并与高效液相色谱分析联用,实现了香兰素和乙基香兰素的快速高效富集和高灵敏度检测,两者的检出限达10μg/L,回收率大于92%。本研究表明,合成的Fe3O4/C N T s磁性复合粒子是一种很好的奶制品中香兰素添加剂的样品前处理富集材料。
hloramphenicol 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 wavelength dispersive X-ray fluorescence (WD-XRF) spectrometry combined with calibration curve method was established for simultaneously analyzing low-Z elements (C,N,O) and Al,Si,Fe in polyamide.To investigate the origin of plastic material causing deposition and blocking in instrument engines and pipelines,polyamide 6 (PA 6,an engineering plastic) was chosen as the study object on account of its common use in industry.The sample preparation with pressed powder disk has been developed for determination of six elements in PA 6.Pure Cu metal was used as the matrix and PA 6 was regarded as standard sample for C,N,O elements.PA 6 particles were firstly smashed to uniform powder in liquid nitrogen,and then mixed with inorganic standard powders (Fe2O3,Al2O3,SiO2,and Na 2 SiO 3).The mixture was ground to obtain homogeneous calibration materials for WD-XRF analysis.The quantitative property of the calibration curve method for each element was reliable.The limits of detection (S/N≤3) of C,N,O,Al,Si and Fe using WD-XRF were 249,120,101,6.2,3.3,and 1.8 μg/g,respectively.To confirm the accuracy of the proposed WD-XRF calibration curve method,inductively coupled plasma optical emission spectroscopy (ICP-OES) detection for Al,Si,Fe and elemental analyzer (EA) analysis for C,N,O were utilized.A good correlation of the WD-XRF results with the measurements of ICP-OES and EA was observed.
