火焰原子吸收测定阿胶中铜的含量

采用微波消解-火焰原子吸收光谱法测定阿胶中铜的含量。微波消解阿胶样品具有方便、快捷、污染少特点,并且可以完全消解样品;方法考查了8种牌号的阿胶产品,方法检出限为0.006μg/mL,方法的加标回收率97.8%~108.0%,相对标准偏差小于2%,结果令人满意。     

微波消解-分光光度法测定茶叶中铜的含量

采用微波消解法预处理茶叶样品,利用二乙基二硫代氨基甲酸钠(DDTC)分光光度法测定其中铜的含量,确定了最大吸收波长、显色剂用量、显色时间、pH值、消解工艺和掩蔽剂等条件,和干法灰化法测定的结果进行对比,本方法具有灵敏度高、精密度好、耗时少、操作简单等优点,相对标准偏差(n=6)在2.2%~5.1%,加标回收率在98.6%~101.3%,结果满意。     

电感耦合等离子体原子发射光谱法测定印染污泥中的重金属元素

选取某印染厂污泥作为样品,经硝酸-高氯酸-硫酸消解体系进行微波消解后,采用电感耦合等离子体原子发射光谱法对样品中铜、铬、锌、镉、铅5种有害重金属元素进行定量分析。方法相对标准偏差小于4.0%,加标回收率在93.8%～108.2%。     

微波消解—原子吸收光谱法测定蓬莱葛中的金属元素

采用微波消解对中草药蓬莱葛进行消解,并在火焰原子吸收光谱仪器最佳工作条件下,用标准曲线法测定其所含锌、铁、铜、钙、铅5种金属元素的含量。结果表明,方法检出限均小于0.0022μg/mL,加标回收率92.2%~110.0%,相对标准偏差RSD≤6.47%。     

微波消解-原子吸收法测定污泥中的铜、锌含量

参考环境标准《固体废物镍铜的测定》和《固体废物铅锌隔的测定》优化了原子吸收仪工作参数和微波消解条件,建立了微波消解-原子吸收法测定太阳能电池行业废水处理后污泥中的铜和锌元素的分析方法,方法的检出限范围为0.001~0.009mg/L,方法加标回收率93.3%~109%,相对标准偏差RSD均小于5%。     

三种消解方式在电感耦合等离子体质谱法同时测定废水中7种重金属元素中的应用研究

电感耦合等离子体质谱法测定废水中铜、锌、铬、镍、铅、镉和铊，采用水浴消解、微波消解和电热板消解方式对样品进行前处理，将测定结果进行比较分析。结果表明：微波消解测得目标物的精密度最高，电热板消解和水浴消解所得结果均偏低。在一定条件下对采集水样进行加标回收测试，微波消解所测元素的加标回收率最好，为97.8%～102%。     

微波消解-分光光度法测定茶叶中铁的含量

采用微波消解法预处理茶叶样品,利用分光光度法测定其中铁的含量,确定了其测试条件:最大吸收波长为510 nm,显色剂用量为3.0 mL,显色时间为15 min和pH=5,并和干法灰化法测定的结果进行对比,方法具有准确度高、精密度好、耗时少、操作简单等优点,相对标准偏差(n=6)在2.5%~3.1%,加标回收率在95.4%~98.0%,结果满意。     

干法灰化消解和ICP-OES法测定糕点中的铝含量

介绍了两种种实用性强的测定糕点中铝含量的方法：干法灰化消解紫外分光光度计比色测定糕点中的铝含量,微波消解电感耦合等离子体发射光谱测定高点中的铝含量。结果表明：两种方法经计算加标回收率和精确度满足要求。干法灰化消解紫外分光光度计比色测定方法操作便捷,检测成本低,ICP-OES稳定性好,但是检测成本高。     

干、湿法消解-火焰原子吸收法测定多种食品中钙元素的含量

经干法灰化、湿式消解两种方法预处理,运用火焰原子吸收法测定多种食品中钙元素的含量。结果表明,钙元素在(1~10)μg·m L-1范围内,线性关系良好,相关系数为0.9932。所测13种食品中,虾皮的钙含量最高,为766.61mg/100g(湿法),香菇的钙含量最低,为5.16mg/100g(湿法)。干法灰化加标回收率在90.20%~103.20%,湿法消解加标回收率在90.50%~104.95%,两者相对标准偏差均小于4%。     

食品考核盲样中锰元素的测定

分别采用微波消解法和湿法消解法消解,用火焰原子吸收光谱仪测定盲样中锰元素含量,对比了不同消解方法对测定结果的影响,并作了方法准确度和精密度考察,微波消解的加标回收率在87. 0%～97. 5%之间,RSD1. 11%～1. 33%(n=5),湿法消解的加标回收率在98. 0%～109. 0%之间,RSD 0. 51%～1. 25%(n=5),两种消解法测定结果差异无统计学意义(P0. 05),上报考核盲样结果分别为1. 18 mg/L和1. 22 mg/L,评价为满意。为保证测定结果的准确性,重点把握样品前处理和质量控制等关键点。     

分解炉扩径的技术改造

我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

A study of miscibility of blends of polybutadienes of varying microstructure

The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure.     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

粉煤灰中烧失量检测的不确定度分析

以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

生物油的成分分析及物性测定

以添加FeCl2的ZnCl2-KCl混合熔盐裂解纤维素和秸秆,制得生物油。采用傅立叶变换红外光谱法和气相色谱-质谱法分析生物油的成分。结果表明,生物油中成分复杂,含有氧元素、多种有机化合物,主要包括酮类、醛类、酚类及羧酸类等。测定了20～80℃生物油的密度和粘度,发现生物油的密度与温度呈较好线性关系,而生物油的粘度均大于水的粘度,且不同熔盐体系对秸秆生物油的粘度无较大影响。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003