Determination of Trace Para Red Residues in Foods through On-Line Molecularly Imprinted Solid Phase Extraction Coupled with High-Performance Liquid Chromatography

ABSTRACT:  In this article, we prepared a novel imprinted polymer by a room temperature ionic liquid-mediated surface molecular imprinting technique in combination with a sol–gel process. This polymer was characterized by static and kinetic adsorption experiments and exhibited good recognition ability and offered fast kinetics for the adsorption of Para Red. A simple and sensitive analytical method, based on the coupling of molecularly imprinted solid phase extraction with high-performance liquid chromatography (HPLC), had been developed for determination of trace Para Red. With a loading flow rate of 0.42 mL min⁻¹ for 25 mL, an enrichment factor of 1061 was achieved. Under the selected experimental condition, the detection limit (S/N = 3) of Para Red was 6.6 ng L⁻¹, and the peak area precision (RSD) for 5 replicate detections of 0.15 μg L⁻¹ Para Red was 4.1%. The applicability of this method for determination of the blank chili sauce sample, spiked with Para Red at 5 to 25 ng g⁻¹ levels, was demonstrated, with recoveries ranging from 86% to 95%.
Practical Application: In this paper, a simple and sensitive analytical method, based on the coupling of molecularly imprinted solid phase extraction with high performance liquid chromatography, had been developed for determination of trace Para Red. It was applied to the analysis of spiking Para Red in chili sauce sample with satisfactory recovery and repeatability. This proposed method has the potential to be used for monitoring the illegal addition of Para Red in foods in the future due to its simple, reliable, rapid, and excellent precision.     

一点红多糖提取工艺的探究

以浸提温度、浸提时间、浸提料液比、浸提次数为主要考察因素,运用正交试验设计,对一点红多糖提取工艺进行研究.结果表明,影响一点红多糖提取率最重要的因素是料液比,最佳提取工艺为：石油醚回流2.5h,滤渣用无水乙醇回流1h脱色并除去小分子多糖,用30倍原料质量的中性水,在温度70℃,提取时间2h下,浸提2次.加入3倍无水乙醇沉淀,用三氯乙酸除去蛋白质,静置12h,得到脱蛋白的多糖液.     

氧化铝厂赤泥的基本物理力学性质

对氧化铝厂新鲜赤泥滤饼、自燃固结赤泥、击实赤泥等354组样品进行含水率、密度、比重、液塑限试验、干密度、孔隙比、饱和度、渗透、固结、固结快剪、三轴剪切试验、颗粒等物理力学指标测试。综合分析研究后得出:新鲜赤泥滤饼的性质类似于粉质粘土,具有高含水率、高饱和度、孔隙比大、力学强度较低的特点;赤泥的颗粒级配较好,均匀性差;赤泥的最优含水率一般为41.6%,最大干密度为1.25g/cm3,在最优含水率时进行击实,击实后抗剪强度指标明显提高;赤泥的力学强度随着赤泥堆存时间的增加而提高。为氧化铝厂赤泥堆存、赤泥尾矿坝建设的初步设计计算提供了基础数据。     

高掺量赤泥-粉煤灰微晶玻璃研究

赤泥是氧化铝生产中排放的碱性废渣,粉煤灰是燃煤电厂排放的高SiO2含量废渣.综合利用两种废渣制备高性能的微晶玻璃材料,控制SiO2含量在31%～44%,CaO含量在25%～31%,两种废渣总吃渣量能够达到90wt%以上,具有显著经济效益和环境效益.     

How Does Negative Life Change Following Disaster Response Impact Distress Among Red Cross Responders?

The American Red Cross is the largest nongovernmental organization responding to disasters in the United States. This study investigated the impact of negative life change occurring in the year following the September 11, 2001, terrorist attacks on levels of distress among 757 Red Cross Disaster Services Human Resources (national disaster team) employees and volunteers who responded to this disaster. Negative life change in the year following disaster response fully mediated the relationship between disaster response and symptoms of depression and partially mediated the responses between disaster response and posttraumatic stress and anxiety symptoms. Results highlight the importance of life experiences in the year following disaster response and, therefore, the education and follow-up services provided to disaster workers prior to and following disaster assignment. Suggestions for monitoring disaster-related stress during and following assignment are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

传统水浴提取紫甘蓝红色素动力学研究

本文通过分析传统水浴提取紫甘蓝红色素的传质机理,建立了提取过程中紫甘蓝红色素得率与各工艺条件的动力学模型。经验证,所建立的动力学理论模型与实测数据相吻合,可良好地模拟色素提取过程,用于指导工业生产。     

纳米TiO2/SO42-的合成及光催化降解性能研究

研究了以工业级钛酸异丙酯为前驱体,正丙醇为溶剂,浓硫酸作催化剂和抑制剂,乙酰丙酮为稳定剂,采用溶胶-凝胶法制备纳米TiO2/SO42-。利用XRD、SEM、FT-IR、UV-vis、N2吸附-脱附测定BET表面积对所制备的材料进行了表征。结果表明:纳米TiO2/SO42-催化剂在可见光区的吸收较强,所制备的催化剂与未经改性的TiO2相比,吸收边从350 nm红移到430 nm左右,其红移效果显著。在紫外灯照射下进行了光催化降解亚甲基蓝溶液的催化剂性能研究,探讨了pH值、反应温度、亚甲基蓝初始质量浓度以及催化剂用量对降解率的影响。结果表明:光催化降解亚甲基蓝在中性条件下的降解率较高,碱性环境下达到最佳;最佳反应温度为35~55℃;初始浓度越大降解率越小;处理30 mL亚甲基蓝溶液所需催化剂为30 mg。     

The use of basalt powder as a natural heterogeneous catalyst in the Fenton and Photo-Fenton oxidation of cationic dyes

The use of naturally present heterogeneous catalysts has recently been an essential issue in the Fenton and photo-Fenton processes. In this study, the uses of basalt as a catalyst for the Fenton and photo-Fenton reactions for methylene Blue (MB) and Basic Red 18 (BR18) degradations were investigated. Basalt was selected because of the presence of the iron (III) oxide in the structure. Basalt was characterized by X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) analysis to obtain the chemical composition and the crystalline phase. The surface charge and the surface area were obtained by zeta potential and Brunauer Emmett-Teller (BET) analysis. Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscope (SEM) were utilized to explore the functional group and the surface morphology. Fenton and photo-Fenton processes were applied to explore the best degradation method. Adsorption was also tested and the adsorption process had minimum removal efficiency (12% for MB and 17% for BR18). The removal efficiencies for MB and BR18 by the Fenton process were 87% and 28%, respectively. The photo-Fenton process had maximum removal efficiency with 100% for MB and 70% for BR18. The optimum conditions were 70 mg/L dye concentration, 5 mM H₂O₂, 1.0 g/L basalt loading and pH 2. Basalt has shown reuse capability as a catalyst for three consecutive cycles.     

冬小麦冠层光谱红边参数的变化及其与氮素含量的相关分析

通过对不同氮肥条件下的小麦植株由上而下进行器官疏剪,分析了不同处理下冠层光谱反射率及其红边参数的变化。结果表明,冠层光谱反射率因不同肥力、不同疏剪处理而有较大的差异,表现出不同程度的红边的“红移”和“蓝移”现象。各处理的红边曲线形状均出现双峰现象,表现为第二个峰值高于第一个峰值,并且均为N1>N2>N0。相关分析表明,随着由上而下的疏剪处理,不同叶位叶片光谱反射率对冠层光谱的贡献增加,并且其红边参数与相应的叶片全氮含量的相关系数也增加,部分达到显著或极显著相关水平。该结果为利用下部缺素敏感叶片的光谱特征进行小麦养分的及时补充提供了可靠的理论依据。     

Use of ozone in detoxification of aflatoxin B1 in red pepper

Red pepper (Capsicum annuum) is one of the most important agricultural products of Turkey. For public health and export requirements, red pepper must be produced free of hazardous contaminants. However, previous investigations showed that red pepper could be contaminated by aflatoxin above the limits that may be critical for health. In this study, use of the high oxidising power of ozone achieved detoxification of aflatoxin. Samples were subjected to ozonation at various ozone concentrations (16, 33, 66 mg/l) and exposure times (7.5, 15, 30, 60 min). In summary, the reductions of content of aflatoxin B₁ in flaked and chopped red peppers were 80% and 93% after exposures to 33 mg/l ozone and 66 mg/l ozone for 60 min, respectively.