Evaluation of a new electrolytic cold vapor generation system for mercury determination by AFS

In this study we firstly report a new electrolytic cold vapor generation system for mercury determination on Pt/Ti cathode in the presence of organic acid catholyte. Comparing with the traditional inorganic acid, formic acid increased the signal intensity of Hg vapor from electrolytic generation on Pt cathode and reduced the impact of cathode erosion on the stability of signal intensity. Moreover, formic acid has better interference tolerance. The introduction location for carrier gas is probably the most important factor that influences the signal intensity of Hg from electrolytic vapor generation. The effects of the electrolytic conditions and interference ions on the ECVG have been studied. Under the optimized conditions, the detection limit (3σ) of Hg (II) in aqueous solutions is 1.4 ng L⁻¹; a relative standard deviation of 2.3% for 1 μg L⁻¹ Hg was obtained. The accuracy of this method was verified by the determination of mercury in the certified reference materials. This system has been applied satisfactorily to the determination of Hg in Traditional Chinese Medicines samples.     

中药致肾毒性成分马兜铃酸A单抗制备及酶联免疫分析方法的建立

采用活化酯法,将马兜铃酸A分别与牛血清蛋白(BSA)和卵清蛋白(OVA)偶联,得到免疫抗原马兜铃酸A-BSA和包被抗原马兜铃酸A-OVA.利用马兜铃酸A-BSA免疫Bal b/c小鼠,制得鼠单克隆抗体1A11,单抗效价为2×104;单抗为IgG1类,轻链为κ型;与其结构类似物马兜铃酸B、C和D的交叉反应率分别为2.8%,3.5%和31.2%.基于抗马兜铃酸A单克隆抗体的间接竞争酶联免疫分析方法(icELISA)的IC50为1.9 μg/L,检测范围为0.5～7.5 μg/L.icELISA添加回收率为86%～97%,相对标准偏差在5.2%～11.1%之间.利用所建立的icELISA测定了6个中药材和5个中成药中马兜铃酸A的含量,并用高效液相色谱法(HPLC)进行了验证,其中关木通、广防己、天仙藤、马兜铃和青木香中均检测出马兜铃酸A,而川木通和5个中成药中未检测到马兜铃酸A.结果表明: 本方法可用于中药中马兜铃酸A的快速检测.     

五种中药中微量元素及重金属元素的含量分析

用微波消解-原子吸收分光光度法对巴戟天、大黄、陈皮、板蓝根、茯苓等5种中药材中的7种金属微量元素进行了含量分析。结果表明,该法的线性良好,重现性在3.3%~11%之间,精密度在2.6%以内,回收率满足定量分析要求;5种药材中铅均未超标,茯苓中镉超出国家标准;5种药材里的铜含量均有超标,其中,巴戟天超标最严重;铁在5种药材中的含量最高,其中以巴戟天含量最为丰富,达到了746.750 mg/kg,其次是锌和锰,铬的含量最少。结论:对5种药材中铜均出现超标,虽然在边缘位置,但应该予以重视;巴戟天中丰富的铁元素,可能在防止癌变发生和发展中起到一定功效。     

FAAS法测定三种中药材中的微量元素

采用V（浓硝酸）＋V（高氯酸）=4＋1混酸溶解消化样品。用火焰原子吸收光谱法（FAAS）测定了红芪、黄芪、板蓝根中K、ca、Na、Mg、Fe、Mn、Zn、Cu8种微量元素的含量。结果表明,红芪中钙的含量最高,铜的含量最低;黄芪和板蓝根中镁的含量最高,铜的含量最低。各元素回收率（n=7）在96．07％～101．26％之间,RSD值（n=7）在0．60％～2．99％之间。     

A rapid in vitro assay of cobalamin in human urine and medical tablets using ICP-MS

A rapid and simple as well as sensitive inductively coupled plasma mass spectrometry (ICP-MS) method for the determination of cobalamin is described. Cobalamin in human urine and medicine tablet solutions was converted on-line into free cobalt ions in acid medium, the cobalt ions were then detected by ICP-MS. Cobalamin was determined by measuring the increase of integral counts per second intensity, which was linear over the cobalamin concentration range of 1.0 × 10⁻¹⁰ g mL⁻¹ to 8.0 × 10⁻⁵ g mL⁻¹, and the limit of detection was 0.05 ng mL⁻¹ (3σ). At the pump rate of 30 rotations per minute, one analysis cycle of cobalamin, including sampling and washing, could be accomplished in 0.5 min with the relative standard deviations of less than 5 %. The proposed procedure was applied successfully in monitoring cobalamin in human urine without any pretreatment process and in rapid determination of cobalamin in multivitamin tablets.     

微波辅助提取-气相色谱法同时测定中草药中有机磷和氨基甲酸酯农药残留

建立了中草药中有机磷和氨基甲酸酯类农药同时检测的气相色谱分析新方法.中药材试样依据正交实验的优化条件,用正己烷-丙酮(1∶4,V∶V)混合提取剂进行微波辅助提取,经弗罗里硅土和中性氧化铝混合层析柱净化后,采用HP-5毛细管柱分离,氮磷检测器同时检测中草药中15种有机磷和6种氨基甲酸酯类农药残留量.21种农药在0.01～1.0 mg/L的浓度范围内线性良好,线性相关系数为0.9950～1.000,检出限为0.002～0.01 mg/L.在0.05、0.2、0.5 mg/kg三个添加水平的平均回收率分别为75.11%～128.57%、75.85%～120.71%和76.43%～117.25%,相对标准偏差分别为 3.10%～10.58%、5.27%～9.94%和4.03%～9.03%.方法用于中草药中有机磷和氨基甲酸酯类农药残留的同时检测,结果良好.     

Multiplexing fibre optic near infrared (NIR) spectroscopy as an emerging technology to monitor industrial bioprocesses

The application of near infrared spectroscopy in bioprocessing has been limited by its dependence on calibrations derived from single bioreactor at a given time. Here, we propose a multiplexed calibration technique which allows calibrations to be built from multiple bioreactors run in parallel. This gives the flexibility to monitor multiple vessels and facilitates calibration model transfer between bioreactors. Models have been developed for the two key analytes: glucose and lactate using Chinese hamster ovary (CHO) cell lines and using analyte specific information obtained from the feasibility studies. We observe slight model degradation for the multiplexed models in comparison to the conventional (single probe) models, decrease in r² values from 89.4% to 88% for glucose whereas for lactate from 92% to 91.8% and a simultaneous increase in the number of factors as the model incorporates the inter-probe variability, nevertheless the models were fit for purpose. The results of this particular application of implementing multiplexed-NIRS to monitor multiple bioreactor vessels are very encouraging, as successful models have been built on-line and validated externally, which proffers the prospect of reducing timelines in monitoring the vessels considerably, and in turn, providing improved control.     

The polyphenolic profiles and antioxidant effects of Agastache rugosa Kuntze (Banga) flower,leaf, stem and root

Agastache rugosa Kuntze (Korean mint) is used as a spice and in folk medicine in East Asia. The present study identified a total of 18 polyphenols from the flower, leaf, stem and roots of this plant using high‐performance liquid chromatography–tandem mass spectrometry. Fourteen of these compounds had not previously been identified in these plant tissues. Each polyphenol was validated in comparison with external calibration curves constructed using structurally related compounds, with determination coefficients >0.9993. The limits of detection and quantification were 0.092–0.650 and 0.307–2.167 mg/L, respectively. Recoveries of 61.92–116.44% were observed at two spiking levels, with 0.91–11% precision, expressed as relative standard deviation (except anthraquinone spiked at 10 mg/L). Hydroxycinnamic acid was the most abundant compound in the root, while the flowers showed the highest total flavonoid level. Antioxidant activities, determined in terms of reducing power, Fe²⁺ chelating activity and the radical scavenging activities using α,α‐diphenyl‐β‐picrylhydrazyl and 2‐2?‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid, increased in a concentration‐dependent manner; the highest activity was identified in the stems, followed by leaves > flowers > roots. These findings indicate that A. rugosa is a good source of bioactive compounds and can be used as a functional food. Copyright © 2015 John Wiley & Sons, Ltd.     

Differentiating parts of Cinnamomum cassia using LC‐qTOF‐MS in conjunction with principal component analysis

Cinnamon bark (Rou Gui in Chinese), cinnamon twig (Gui Zhi) and shaved cinnamon bark (Gui Sin) have been widely used as spices and in traditional Chinese medicine since ancient times. On‐going issues related to quality and authenticity necessitate the development of analytical methods capable of providing an objective evaluation of samples. In this study, chemical fingerprints of cinnamon bark, cinnamon twigs and shaved cinnamon bark were established using liquid chromatography quadruple time‐of‐flight mass spectrometry in conjunction with principal component analysis (PCA). From 125 samples of cinnamon, we identified the following eight compounds and their the detection ratios: coumarin, cinnamaldehyde, cinnamyl alcohol, cinnamic acid, 2‐hydroxycinnamaldehyde, 2‐hydroxycinnamic acid, 2‐methoxycinnamaldehyde and 4‐methoxycinnamaldehyde. Of these, 4‐methoxycinnamaldehyde presented the largest variations in detection ratio, making up 64.0, 97.4 and 50.0% in cinnamon bark, cinnamon twig, and shaved cinnamon bark, respectively. The quantities of cinnamyl alcohol, coumarin and cinnamaldehyde also varied between the three parts of the plant. Chemical fingerprints of the three cinnamon samples were established using principal component analysis, the results of which indicate that cinnamon bark and shaved cinnamon bark could be easily differentiated, despite a marked similarity in outward appearance. Cinnamon twig was also shown to depart from the other clusters. The proposed method provides a fast and efficient means of identifying cinnamon herbs for quality control purposes. Copyright © 2016 John Wiley & Sons, Ltd.     

荧光淬灭和加强理论公式合理性的热力学分析

通过荧光法在不同温度下研究了3种第三代头孢新药: 盐酸头孢吡肟、头孢匹胺和头孢唑肟钠与人血清白蛋白(HSA)和牛血清白蛋白(BSA)的作用, 分别应用荧光淬灭和荧光加强理论公式计算了它们的结合常数等, 进而分别计算了它们的热力学函数. 因对应于不同的理论公式得出的K_A值并不完全相同, 由此得到它们相应的热力学参数也有所不同. 本文对这些热力学数据的差异进行了分析比较, 结果表明: 基于荧光加强理论公式(4)获得的热力学数据显示更为合理. 因而我们建议, 即使在研究受体-底物的荧光淬灭反应时, 采用荧光加强理论公式(4)可以获得更符合实际的结果.