首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 156 毫秒
1.
水中总磷量的密闭微波增压消解快速测定   总被引:4,自引:0,他引:4  
研究了用聚四氟乙烯密封带密封容器,利用微波加热技术,在较高的温度和压力下消解样品,快速测定环境水样中总磷量的方法;讨论了微波功率、微波消解时间、酸度等因素对测定结果的影响,与标准方法对照,经t检验法及F检验法检验,测定结果没有显著性差异,多次加标回收率在98%-103%之间,相对标准偏差≤1.3%,结果令人满意;该法具有操作简便、快速、不污染环境、宜于大批量样品的测定、便于推广普及等优点,可用于其它样品的分析测定。  相似文献   

2.
微波加热溶样技术已应用到矿样的分解中[1],文献[2]曾采用微波密闭深样技术测定矿石中金.  相似文献   

3.
双硫腙-四氯化碳萃取比色法测定锑矿中微量铅,矿样分解多采用酸溶法,即用盐酸-硝酸-酒石酸钾钠或者王水分解矿样。这对于精锑矿和锑锭较易得到清液,而对其它锑矿就很难办到,有的矿样甚至分解不完全,即使能分解完全,有的酸不溶残渣吸附部分铅,致使测定不易得到满意的结果。本文在这方面作了一些探讨,用碱熔法分解矿样,酸化水提取液,用氨水调pH8—9左右除硅,然后进行铅的比色。此法简单、快速,结果稳定,重现性好。制备试液约需1小时。一、熔样方法  相似文献   

4.
周西林  董萍 《分析试验室》2008,27(Z1):213-214
采用微波消解样品处理技术,结合光度法测定硼铸铁中的硼元素,该方法与传统的酸溶法 熔法样品处理相比,不但分析结果相吻合,而且更具有快速、高效、清洁和污染少等优点,完全能满足铸铁分析的要求,不但分析结果相吻合,而且更具有快速、高效、清洁和污染少等优点,完全能满足铸铁分析的要求。  相似文献   

5.
微波技术用于腐败动物组织中吗啡的检测研究   总被引:3,自引:0,他引:3  
采用微波酸水解和微波酶水解的方法,建立了一套检测腐败动物组织中吗啡的方法。与传统的水浴加热水解相比较,微波水解大大缩短了水解时间,能够使吗啡与蛋白充分解离。该方法具有快速,灵敏度、精确度和准确度高的特点,适合大批量腐败生物检材的标准化分析测定,并成功应用于一些案例的检测工作,取得了良好的效果。  相似文献   

6.
微波消解/等离子体发射光谱法测定宁夏枸杞中的多元素   总被引:8,自引:2,他引:8  
采用微波消解ICP—AES法同时测定了宁夏枸杞中14种微量元素的含量,并对样品的前处理条件进行了探讨,通过添加标准回收实验,验证了分析数据的可靠性。结果表明,该法快速、简便、数据准确可靠,结果令人满意,适合常规分析。  相似文献   

7.
建立了微波辅助萃取-气相色谱-质谱联用测定大气可吸入颗粒物中痕量多环芳烃(PAHs)的分析方法,优化了萃取时间、溶剂用量、微波辐射功率等微波萃取条件,并与超声波萃取方法进行了对照研究。结果表明:除了苊、芴外,微波萃取方法的回收率在85%-130%之间;方法的检出限在0.002-0.016μg/m^3之间。通过实际样品中PAHs的分析表明,该法快速、溶剂用量小,满足痕量分析的要求。  相似文献   

8.
本文试验了以碳酸钠-硼酸混合熔剂分解矿样,亚硫酸钠还原三价铁,硫酸高铈标准溶液滴定,测定铁矿石中总铁量的各种条件,方法既革除了汞盐、铬盐对环境的污染,又极其简便、快速,经用不同标准矿样反复测定10次,计算其标准偏差(S),其值不大于0.105,用于生产实践,经外检,证明其准确度亦不低于日常例行分析的误差要求。  相似文献   

9.
微波消煮快速测定土壤中的酚类化合物   总被引:8,自引:0,他引:8  
微波消煮快速测定土壤中的酚类化合物范彩玲,高岐,高向阳,朱灵峰(河南农业大学基础部,郑州450002)目前,微波技术已广泛的应用于分析化学领域 ̄[1],由于该技术消解样品快、完全,不污染环境,所以,越来越受到人们的重视。土壤中酚类比合物的测定,经典方...  相似文献   

10.
微波加热法测定粮食中的水分   总被引:7,自引:0,他引:7  
采用微波加热法测定粮食中的水分,测定条件是:微波功率700w、加热时间8min。测定结果的标准偏差为0.023%~0.047%(n=5)。该方法操作简便,分析时间短,分析结果准确、可靠。  相似文献   

11.
Understanding the transport of trace elements through a coal-fired power plant requires reliable analytical methods for these elements in all the ingoing and outgoing mass streams. Coal and different kinds of ashes comprise the most abundant mass streams in such a plant. As a continuation of our previous work, we have optimised a digestion method for the AAS determination of heavy metals in coal samples. It has become evident that complete dissolution of metals in coal samples and accurate results in subsequent analysis can be obtained by means of applying pressurised digestion under microwave heating. The combination of HNO3 (conc.) and HF (conc.) in the volume ratio of 50?:?1 attacked the sample well enough, and good recoveries for all the metals studied were obtained. Surprisingly good results were obtained also when HNO3 alone was used as the digestion acid.  相似文献   

12.
Understanding the transport of trace elements through a coal-fired power plant requires reliable analytical methods for these elements in all the ingoing and outgoing mass streams. Coal and different kinds of ashes comprise the most abundant mass streams in such a plant. As a continuation of our previous work, we have optimised a digestion method for the AAS determination of heavy metals in coal samples. It has become evident that complete dissolution of metals in coal samples and accurate results in subsequent analysis can be obtained by means of applying pressurised digestion under microwave heating. The combination of HNO3 (conc.) and HF (conc.) in the volume ratio of 50 : 1 attacked the sample well enough, and good recoveries for all the metals studied were obtained. Surprisingly good results were obtained also when HNO3 alone was used as the digestion acid. Received: 18 June 1998 / Revised: 23 September 1998 / Accepted: 24 September 1998  相似文献   

13.
Most conventional digestion procedures, such as dry ashing and wet ashing, are tedious and labor intensive. Microwave digestion is a good alternative, because microwave dissolution is faster, safer, and simpler, and provides more controlled reproducible conditions than conventional methods. The purpose of this study was to develop a microwave digestion method for mineralizing meat and bone meal diets, feces, and ileal contents. Each sample was heated on a hot plate for 10 min, dry ashed at 65 degrees C for 4 h, and transferred into microwave vessels. Then, 10 mL 70% HNO3 was added. Samples were digested for 7, 10, and 20 min at 95, 90, and 85% power, respectively. After the heating cycle, 6 mL 30% H2O2 was added, and samples were returned to the microwave for a second heating cycle of 1 and 7 min at 95% and 90% power, respectively. Finally, chromium concentration was determined by flame atomic absorption spectrophotometry. The digestion method was validated by using a standard reference material, SRM domestic sludge 2781, with a certified chromium value of 195 +/- 9 micrograms/g. The value obtained in this study was 178 +/- 11 micrograms/g, for a difference of 17 micrograms/g. Spike recovery experiments resulted in 103.16 and 100.35% recoveries of chromium from diet and feces samples, respectively. Coefficients of variation were 10.8 and 7.8%, respectively.  相似文献   

14.
合成了离子液体氯化1-(2-羟乙基)-3-乙基-咪唑([HeEIM]Cl), 并利用FTIR和1HNMR对其化学结构进行了表征. 考察了NaOH、微波和高压等处理方式对棉纤维的结晶度、聚合度(DP)和溶解率的影响. 研究了不同的溶解温度在微波加热和传统加热条件下对棉纤维的溶解率和再生纤维素的聚合度的影响. 利用FTIR, XRD, TGA和SEM等方法分别对溶解后得到的再生纤维素的化学结构、结晶度变化、热稳定性和表观形貌进行了分析. 结果表明, 合成的离子液体对棉纤维表现出很好的溶解能力, 且在溶解和再生过程中未发生化学变化. 棉纤维在高压条件下经质量分数为30%的NaOH预处理后, 溶解性能最佳. 微波加热法的溶解效果远远优于传统加热法, 且随着温度的升高, 溶解率逐渐增大. 溶解后得到的再生纤维素的结晶度变小, 聚合度下降, 热稳定性降低.  相似文献   

15.
Jordanov N  Nikolova B  Havezov I 《Talanta》1978,25(5):275-278
The dissolution of an iron-containing substance in orthophosphoric acid either alone or mixed with nitric acid or nitric acid-sulphuric acid mixture at 270-280 degrees has been examined, to determine the composition of the solutions which are used for analytical determinations. The possibility of condensation of H(3)PO(4) and formation of polyphosphoric acids during the dissolution has been proved. Solutions which may contain pyrophosphoric acid, tripolyphosphoric acid and tetrapolyphosphoric acid have been obtained. The exact composition of these solutions depends on the initial H(3)PO(4) concentration, the heating time, and, in some cases, the presence of nitric acid and sulphuric acid. It is assumed that the nitric and sulphuric acid affect the loss of water and therefore the thermal dehydration of the orthophosphoric acid during the dissolution. No qualitative changes in the phosphoric acid composition have been observed in the presence of Fe(III). Formation of Fe(III) polyphosphates is assumed.  相似文献   

16.
Ag2SO4-CuSO4 催化-微波消解快速测定炼油污水中化学需氧量   总被引:9,自引:1,他引:8  
以Ag2SO4-CuSO4为催化剂,探讨了微波消解测定炼油污水中化学需氧量(Chemical Oxygen Demand,CODcr)的方法。确定了微波消解测定炼油污水CODcr的最佳条件;消解功率、消解时间、混酸介质H3PO4-H2SO4用量、催化剂配比等。用该方法测定炼油水各处理装置出水 的CODcr,与经典的CODcr回流法所得结果一致。方法适用于临控生产过程。  相似文献   

17.
研究了一种制备锂离子电池正极材料Li2FeSiO4的新方法. 采用机械球磨结合微波热处理合成了Li2FeSiO4正极材料. 通过XRD、SEM和恒流充放电测试, 对样品结构、形貌和电化学性能进行了表征和分析. 与传统固相法合成的材料在晶体结构、微观形貌以及充放电性能方面进行了比较. 结果表明, 微波合成法可以快速制备具有正交结构的Li2FeSiO4材料; 在650 ℃时处理12 min, 获得了纯度高、晶粒细小均匀的产物, 该产物具有较高的放电比容量和良好的循环性能. 在60 ℃下以C/20倍率(电流密度, 1C=160 mA·g-1)进行充放电, 首次放电容量为119.5 mAh·g-1, 10次循环后放电容量为116.2 mAh·g-1. 与传统高温固相法相比, 微波合成法制备的材料具有较高的纯度、均匀的形貌和较好的电化学性能.  相似文献   

18.
微波合成法制备锂离子电池正极材料Li2FeSiO4   总被引:4,自引:0,他引:4  
研究了一种制备锂离子电池正极材料Li2FeSiO4的新方法.采用机械球磨结合微波热处理合成了Li2FeSiO4正极材料.通过XRD、SEM和恒流充放电测试,对样品结构、形貌和电化学性能进行了表征和分析.与传统固相法合成的材料在晶体结构、微观形貌以及充放电性能方面进行了比较.结果表明,微波合成法可以快速制备具有正交结构的Li2FeSiO4材料;在650 ℃时处理12 min,获得了纯度高、晶粒细小均匀的产物,该产物具有较高的放电比容量和良好的循环性能.在60℃下以C/20倍率(电流密度,1C=160mA·g-1)进行充放电,首次放电容量为119.5 mAh·g-1,10次循环后放电容量为116.2 mAh·g-1.与传统高温固相法相比,微波合成法制备的材料具有较高的纯度、均匀的形貌和较好的电化学性能.  相似文献   

19.
微波消解-石墨炉原子吸收光谱法测定蜂胶中铅   总被引:1,自引:0,他引:1  
提出了石墨炉原子吸收光谱法测定蜂胶中铅含量的方法,样品采用微波消解,用磷酸二氢铵基体作为改进剂,方法的精密度(n=7)在1.1%~1.3%之间,回收率在91.8%~101.9%之间。  相似文献   

20.
A novel one-step chemical method for preparation of copper nanofluids   总被引:11,自引:0,他引:11  
This paper presents a novel one-step method for preparing of copper nanofluids by reducing CuSO(4).5H(2)O with NaH(2)PO(2).H(2)O in ethylene glycol under microwave irradiation. Nonagglomerated and stably suspended Cu nanofluids are obtained. The influences of CuSO(4) concentration, addition of NaH(2)PO(2), and microwave irradiation on the reaction rate and the properties of Cu nanofluids were investigated by transmission electron microscopy, infrared analysis, and sedimentation measurements. It is found to be a fast, efficient one-step chemical method to prepare Cu nanofluids.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号