微波消解-微波等离子体原子发射光谱法测定原油中6种元素含量

本研究建立了微波消解-微波等离子体原子发射光谱法测定原油中的镍（Ni）、钒（V）、铁（Fe）、钠（Na）、钾（K）、钙（Ca）的方法。对样品量、消解体系及消解温度控制进行了选择实验,确定0.2 g样品,6 mL硝酸+2 mL双氧水消解体系及消解程序;铁、钾、钠、钙、镍的检测浓度范围为0～2 mg/L;钒的检测浓度范围为0～5 mg/L;铁、钾、钠、钙方法检出限为5 mg/kg;钒、镍的方法检出限为2 mg/kg。方法的精密度为1.14%～5.13%,加标回收率范围为81.2%～109.6%,与标准方法对比结果无显著性差异,表明该检测方法能够满足口岸检测需求。     

电感耦合等离子体原子发射光谱法测定塑料及其制品中铅、汞、铬、镉、钡、砷

建立了一种对各种塑料及其制品中铅、汞、铬、镉、钡和砷有害元素总量的快速检测方法.样品采用微波消解进行消化,消解后的溶液用电感耦合等离子体原子发射光谱仪(ICP-AES)进行元素检测.方法的检出限为:铅5.5mg/kg、汞3.0mg/kg、铬3.4mg/kg、镉0.5mg/kg、钡3.2mg/kg、砷7.9mg/kg.各种有代表性塑料样品的元素回收率在86.5%～113.6%之间.根据8个实验室3次平行测定数据计算本方法在相应浓度水平的精密度数据Sr、SR、r、R均满足痕量分析要求.此方法可避免塑料的不完全消解及汞、砷等元素的损失,又能快速定量测定样品中的有害元素,快速有效,易于推广.     

微波消解-石墨炉原子吸收法对大米中铅镉的测定

目的:选取微波消解-石墨炉原子吸收法测定大米中含有的铅镉量。方法:经微波消解预处理的样品,在石墨炉原子吸收法的使用下测定含有的铅镉量。结果:大米中含有0.080 mg/kg的铅和0.092 mg/kg的镉,加标回收率98%～101%,相对标准偏差未超过2.5%,该方法有较佳的精密度、准确度。结论:在测定大米中含有的铅镉量时,选用微波消解-石墨炉原子吸收法能得到准确、可靠的结果,十分适用。     

微波消解-原子荧光光谱法测定煤中砷含量

应用微波消解和原子荧光光谱法测定煤中砷。通过对微波消解和原子荧光光谱法的实验条件进行优化,确定了最佳实验条件。方法的线性范围为0.4-200 ng/mL,相关系数r为0.9994,方法检出限为0.12ng/mL,定量限为0.36ng/mL,方法回收率为94.87%-96.80%,RSD%≤3.20%。该方法操作简单、快速、灵敏度高,可用于煤样品中砷含量的测定。     

微波消解-氢化物发生与ICP-AES法测定鳗鱼中的汞

采用微波消化仪,硝酸-过氧化氢体系消解鳗鱼样品后,氢化物发生器还原发生汞蒸气导入ICP-AES进行测定.方法检出限为0.006mg/kg,回收率为105%～88%,RSD%为3.4%～4.8%.与氢化物发生-原子吸收法结果比较,相对相差＜10%,结果令人满意.     

电感耦合等离子体质谱法测定石膏及其制品中铅、镉等10种元素

通过对进出口石膏及其制品特性的研究,摸索出适合石膏及其制品消解的方法,并对传统的仪器方法进行分析比较,最终确定了完整的检测路线。实验中试样经酸消解后过滤得到澄清溶液,用电感耦合等离子体质谱仪对试液中的铅、镉、铬、砷、汞、铜、锌、锰、镍、钴进行测定,10种元素的检出限和定量限分别为0.07mg/kg和0.2 mg/kg,加标回收率为87.0%-104.1%,相对标准偏差均小于10%。     

干法灰化和微波消解-火焰原子吸收法测定大米中锌元素的比较研究

采用干法灰化与微波消解法对大米样品进行前处理,并用火焰原子吸收光谱法对样品中的锌元素含量进行测定比较。试验表明:不同的消解方法对测定结果有一定程度的影响,但结果数据差异不大。微波消解法的精密度RSD为1.7%,干法灰化法的精密度RSD为3.0%,回收率都在98%～105%。微波消解法相对于干法灰化法精密度较高,回收率差异不大,并具有试剂用量少,工作效率高等优点。     

微波消解-分光光度法测定米面食品中的铝含量

目的:探讨米面食品有害物质铝测定中,分光光度法的构建及应用效果。方法:采用铬天青S作为显色剂,构建微波消解对样品进行前处理,对显色反应最佳条件进行明确;并取米粉、油条和馒头作为试验样品,进行精确度和准确度验证。结果:波长范围为620 nm,乙酸乙酸钠缓冲液8 mL,显色时间20 min为最佳实验条件;标准曲线线性范围为0.5~6μg,r=0.998 5;米粉、油条和馒头中铝含量RSD分别为2.5%、1.3%、3.4%;铝含量的加标回收率为90.5%~102.0%。结论:微波消解-分光光度法具有较高灵敏性和重现性,是可用于米面食品中铝的测定。     

微波萃取-HPLC法测定电子电气产品中的多氯萘

[目的]建立了微波萃取法提取-HPLC法检测电子电气产品中的多氯萘的方法。[方法]样品以甲苯为溶剂经微波萃取法提取、硅胶小柱净化、浓缩后采用高效液相色谱法测定,以外标法进行定量。[结果]方法检测低限为2.5 mg/kg,测定结果的相对标准偏差为2.9%-5.2%,回收率为74.2%-96.8%。[结论]本文所用方法操作简便、快速、准确,对实际样品的检测结果满意。     

微波消解-电感耦合等离子体质谱法测定芦笋罐头13种元素

本文建立了微波消解-电感耦合等离子体质谱法同时测定芦笋罐头中钙、钴、铬、铜、铁、钾、镁、锰、钠、镍、硒、锶和锌13种元素。采用硝酸-过氧化氢酸体系对样品进行微波消解,利用ICP-MS测定上述元素,以内标法改善基体效应及干扰,通过标准曲线计算含量13种元素校正曲线线性关系良好,回收率符合要求。本文所建立的方法准确、可靠。微波消解-电感耦合等离子体质谱法为芦笋罐头的开发和利用提供了科学依据。     

面制食品中铝含量测定方法

探讨如何应用当前的检测标准为食品中含铝添加剂的管理提供更好的技术支持。运用电感耦合等离子体光谱和质谱技术,检测其铝含量,同时比较在不同酸消解体系中对铝含量的测定值产生的影响。结果表明,单一的硝酸体系无法彻底分解样品,必须添加一定量的氢氟酸才能对面制食品中的铝含量作出准确的测算。     

Comparative performance of polyester,polypropylene and chlorofibre thermal fabrics in simulated consumer use

Polyester, polypropylene, chlorofibre/acrylic and polypropylene/acrylic/wool thermal fabrics were compared for water absorption/wicking, pilling and relaxation following elongation. The polypropylene fabrics did not absorb water. Wicking was related to the mass of all but the polypropylene/acrylic/wool fabric, which had a structure unlike that of any of the other fabrics. The polypropylene/acrylic/wool blend had the optimal resistance to pilling, least dimensional change in laundering and negligible growth after elongation.     

Food Shopping Profiles of Career-oriented,Income-oriented,and At-home Wives

The purpose of this study was to develop comprehensive food shopping profiles of career-oriented, income-oriented, and at-home wives. Discriminant analysis revealed distinct profiles for the career-oriented and at-home wives. However, income-oriented wives were similar to career-oriented wives regarding some demographic characteristics, shopping patterns, and some shopping strategies, and similar to at-home wives for other shopping strategies. Income-oriented wives were more likely to have husbands who shared the food shopping role. Overall, the findings of this study suggest that measures of food shopping strategies be refined and that replication of the methodology be used with samples varying in family structure.     

Sensory characteristics of fufu prepared with cassava roots (Manihot esculenta Crantz) stored in polyethylene sacks

This study was carried out to assess the effect of storage of cassava roots in polyethylene sacks for periods of 2, 4, 6 and 8 weeks on the sensory characteristics of cassava fufu, a popular Ghanaian dish. Freshly harvested cassava roots were dipped in tap water and packed into polyethylene sacks in 2‐kg batches and stored at room temperature (25°C ± 1°C). Samples of fresh cassava fufu were evaluated and then at two weekly intervals for a period of 8 weeks. Attributes evaluated were colour, smell, elasticity, smoothness and taste. A structured six‐point ranking scale ranging from 6 (excellent) to 1 (very poor) was used for the evaluation. The data were analysed using analysis of variance, and the least significance difference test at P < 0.05 was used to determine differences between means. The results showed that storage of cassava roots for up to 8 weeks did not significantly affect the colour, smell, elasticity and taste of cassava fufu. However, smoothness of fufu prepared with cassava stored for 6 and 8 weeks was significantly different from the samples of the fresh cassava, and those stored for 2 and 4 weeks. It was concluded that cassava roots stored for periods up to 8 weeks in polyethylene sacks produced fufu of similar characteristics as fresh cassava fufu. This method is therefore recommended for use by homemakers, food service operators, cassava retailers and processors to save them time, energy and money used for the frequent trips for purchases. The method would also reduce post‐harvest losses to a large extent.     

氯化聚乙烯的生产应用及市场分析

介绍了氯化聚乙烯的性能、生产方法和用途,分析了我国氯化聚乙烯的生产消费现状及市场前景,提出了发展我国氯化聚乙烯生产的建议.     

Unveiling ways to reach organic purchase: Green perceived value,perceived knowledge,attitude, subjective norm,and trust

This paper aims to investigate organic food consumption based on the perspectives of an extended research model by integrating the theory of consumption value (TCV) and the theory of reasoned action (TRA). First, we tried to find out how five consumption values of functional, social, emotional, conditional, and epistemic in classic TCV influence consumption choice especially in the sustainable consumption domain of organic food, interpreted as green perceived value (GPV) in the reflective-reflective second-order latent. Second, as an attempt to extend the classic TRA, this study included trust and perceived knowledge in the research model in addition to the subjective norm, attitude, and behavioral intention. A partial least square structural equation method (PLS-SEM) was adopted to examine our research model with 251 samples. Our results revealed that GPV significantly affects consumer attitudes. Consumer attitudes and subjective norms also have a significantly positive effect on purchase intention. As an extended TRA, GPV has a significantly positive effect on trust while trust significantly impacts purchase intention. Further, perceived knowledge positively influences attitude and trust. By jointly considering TCV and TRA, this study proposes several implications emphasizing how GPV and perceived knowledge affects consumers’ organic food consumption choice based on the role of increased trust.     

The interrelationships among service quality,customer satisfaction,and customer loyalty: Examination of the fast-food industry

The purpose of this study was to use customers’ perspectives to develop a conceptual model for improving service quality and enhancing customer satisfaction and loyalty. The 197 samples were selected from customers of leading fast food franchise enterprises in Taiwan. The research results indicate that service quality positively influences customer satisfaction and customer loyalty. Service quality positively influences customer loyalty through customer satisfaction. The research findings indicate that managers need to ensure they have efficient service quality to enhance customer satisfaction and customer loyalty levels.     

Assessing the effect of organic-food short storytelling on consumer response

This study explores the influence of organic food storytelling on consumer response. A random sampling method was used to select organic food retail stores and markets, and then collected 578 valid samples by a quota sampling method. Four storytelling types, including individual story, environmental story, price story, and food therapy story, were based on interview results. Based on partial least squares results, organic food storytelling indeed led consumers to prefer natural food, with food therapy storytelling being the most important factor that influenced their preference for natural food. This was followed by environmental story, price story, with the individual story being the last one. Except for the individual story type, the other three story types established more positive consumer attitudes toward organic food. The preference for natural food increased consumers’ purchase intention, followed by attitude toward organic food, and finally by individual story.