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91.
本文将离子电极与流动注射分析相结合,利用30℃下,在强碱性介质中,果糖和葡萄糖与2,4-二硝基酚钠反应速度明显差异,动力学测定了葡萄糖存在下果糖的含量。自制了2,4-二硝基酚电极作为动力学电位测定用的工作电极。本法测定果糖的范围为0.02~1.00mol/L,其RSD为4.0%~4.9%,RE为1.0~5.0%;当C葡/C果≤3倍时,葡萄糖的干扰不超过5%;本法也曾成功地用于果葡萄浆测定,其RSD  相似文献   
92.
羧甲基纤维素系列高分子表面活性剂超声合成的研究   总被引:27,自引:2,他引:27  
研究了在超声波作用下羧甲基纤维素的降解反应及CMC与具有不同亲水亲油比值的活性大单体「烷基醇(酚)聚氧乙烯醚丙烯酸酯及第三单体」的超声共聚反应。经萃取提纯的共聚产物用IR,^13C NMR和UV等方法进行表证,证实通过超声反应制得了二元和三元共聚物。  相似文献   
93.
IntroductionDuring recent years,organophosphorus pesticides(OPPs)have been widely used in agriculture becauseof their low environmental persistence and high effec-tiveness.However,they have a high acute toxicity.Trace amounts of OPPs may remain in foodstu…  相似文献   
94.
Summary The development and subsequent validation of an isocratic high-performance liquid chromatographic (HPLC) procedure employing ultraviolet (UV) detection for the determination of degradation products in Dipyridamole Injection is reported. The development of this assay involved the evaluation of several factors including buffer type, ionic strength, pH, organic composition, and column type. The described method is simple, reproducible, accurate, and selective. The precision, relative standard deviation (RSD), amongst five sample preparations for total degradation products was not more than (NMT) 10.2 %, while the individual degradation products were NMT 12.1%. Intermediate precision, as determined from fifteen sample preparations, generated by two Analysts on different HPLC systems over three days, exhibited an RSD for total and individual degradation products of 8.2 % and NMT 27.5 %, respectively. The mean absolute recovery of dipyridamole using the described method is 102.1±1. 9%, (mean±SD, n=12) over the concentration range of 0.03 % to 5.0 % of its label claim of 5 mg mL−1. The limit of detection and limit of quantitation were 0.1 and 0.3 μg mL−1, respectively. The linearity of the peak response was verified with respect to dipyridamole concentration over a range of 0.3 and 50 μg mL−1 (0.03 % to 5.0 % label claim). The Standard and Assay Preparations are stable for up to 48 hours at room temperature. The selectivity was evaluated by subjecting the finished product (Dipyridamole Injection) to thermal, acidic, basic, oxidative and fluorescent radiation stress conditions. No interference in the analysis of degradation products was observed, showing the method is stability-indicating.  相似文献   
95.
A flow injection (FI)-reduced volume column system was developed for hemoglobin (Hb) typing to be used as an initial screening method for thalassemia. The column was packed with 140 μl diethylaminoethyl (DEAE)-Sephadex A-50 ion exchange beads. Hb can be separated using Tris–HCl buffer solution with pH gradient 8.5–6.5 and then monitored spectrophotometrically at 415 nm. The hemolysate of 40 blood samples from packed red cells were screened for thalassemia by determining the amount of HbA2 and HbE present. The proposed system was able to predict positive test results from those samples with β, E-trait and EE homozygous thalassemia, Hb types that were independently identified following the conventional method at the hospital laboratory. Advantages of the proposed system over the conventional column technique include low amount of reagents and blood sample needed, short analysis time and low cost. Each analysis required only 80 μl of 50 times diluted packed cells, which is equivalent to 1.6 μl undiluted packed cells, and it can be completed in only 35 min. This simple FI-reduced volume column system was demonstrated to be an economic alternative system for Hb typing to initially screen some types of thalassemia such as β-trait, E-trait and EE-homozygous which are commonly found in Thailand.  相似文献   
96.
提出了同时测定铜基合金中铝和铁的流动注射分析法。以0.04mol/LHCl作载液,铬天青S为显色剂,通过测定628nm处铝、铁两配合物的吸光度之和及铝配合物的吸光度,实现了两组分的同时测定。在优化的实验条件下,检测限:Al和Fe分别为1.69×10-3和1.73×10-3mg/L,Al浓度在0~0.8mg/L;Fe浓度在0~1.0mg/L时服从比耳定律。进样频率为60样/h,所拟方法用于实际样品分析,获得满意结果。  相似文献   
97.
反相流动注射化学发光法测定单宁   总被引:8,自引:0,他引:8  
在碱性介质中 ,单宁对高碘酸钾氧化鲁米诺的化学发光反应有较强的增敏作用 ,据此建立了反相流动注射化学发光测定单宁的新方法 ,并研究了最佳反应条件。该方法快速、准确、线性范围宽 ,测定单宁的检出限为 1 .1 2× 1 0 - 9g/ m L,方法的线性范围为 2 .0× 1 0 - 8~ 6 .0× 1 0 - 6 g/ m L,对于 4.0× 1 0 - 6 g/ m L单宁 1 0次测定的相对标准偏差为 0 .79%。应用于中药五倍子、诃子中单宁的测定 ,结果满意  相似文献   
98.
本文利用所设计的一种新型流动注射液-液萃取重力分相器,建立了流动注射液溶剂萃取原子吸收光谱法测定铅的新方法,详细地研究了流动注射在线萃取的实验条件及流路系统,方法的精密度和检出限分别为2.5%(n=11)和2.8μg/L(k=3)。用拟定的方法测定了峰蛹,粮食等生物样品中的铅,结果与参考值相吻合。  相似文献   
99.
A mathematical model for fitting the experimental ICM (integrated conductimetric method) curves developed by the authors in a previous work, is presented for the first time in this study. The proposed model fits the experimental curves with great precision and allows to predict physical dispersion for single-line flow injection system. The correlation of the model’s parameters with typical reactionless FIA peak parameters is also assessed. The IDQ coefficient—a novel dispersion estimator previously reported by the authors—can also be predicted when operational FIA variables are changed. Experimental and modelled profiles are compared as a function of the system’s variables, showing an excellent agreement.  相似文献   
100.
Sample evaporation in splitless injection of large volumes is rapid: depending on the experiment, results indicate that 200 μl of hexane, for instance, evaporates in 2–10 s, producing vapor at a rate of many hundreds of milliliters per minute. A 60 × 4 mm packed bed of 20–35 mesh Tenax TA enabled injection of 200 μl volumes of all solvents tested, and even 1 ml injections were possible provided they were performed over a period of 30 s. Retention of volatile sample components depends on the sample solvent, the injection volume, and the injection speed, but only little on the injector temperature. Losses of n-tridecane varied from hardly 15 % (when dissolved in pentane) to ca 60 % (ethyl acetate); losses of n-heptadecane were usually below 20 %. The column temperature during injection should be at least ca 20–30°C above the standard solvent boiling point.  相似文献   
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