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无需标准溶液的酸碱滴定计算分析研究 总被引:11,自引:1,他引:10
张云 《高等学校化学学报》1993,14(11):1514-1517
无需标准溶液的滴定计算分析能同时求出滴定剂与被测物质浓度.本文用非线性规划问题的单纯形加速法对无需标准溶液的酸碱滴定进行了研究.单元酸、多元酸及混合酸的测定得到了比较满意的结果. 相似文献
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多元线性回归已广泛用于多组份分光光度分析。本文首次提出在定pH滴定条件下,混合酸各组分浓度与滴定剂体积和溶液pH值之间关系的数学模型,采用多元线性回归求解,可方便地计算出混合酸各组分浓度。该法不需知道被测酸的离解常数,通过对二元、三元及四元混合酸体系分析,证明该法计算方便、分析准确度较好,适用于多组分混合酸的同时分析。 相似文献
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在离子选择电极法中,加入标准法的误差公式尚未见报导。Karlberg认为在一次加入标准法中,电位变化值ΔE应大于0小于65毫伏;Baumann则认为应保证ΔE≥40毫伏,加入标准溶液的体积不大于1毫升。这些结论只是作者的一种估计,缺乏用误差公式加以理论说明。本文从考虑了各种影响因素时的一次加入标准法的定量公式,推导出它的误差公式,为选择一次加入标准法的适宜工作条件提供理论根据。 相似文献
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利用氟离子选择电极,采用一种改进的标准加入法的数据处理方法测定湖北宜昌几种茶叶中的氟含量.与传统的标准加入法不同的是:以加入标准溶液后测得溶液中待测物质(如:氟离子)的总质量(样品及加入标准液后氟离子的质量之和)对加入标准液的中该物质的质量(标准液中氟离子的质量)作图.湖北宜昌某品牌茶叶中的氟含量为46.8±0.5 mg/kg,相对标准偏差(RSD)为0.79%,加标回收率在98.0%~102.5%之间.改进后的标准加入法的数据处理方法简单、快速,能够提供更多的信息(如:加标回收率). 相似文献
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长光路光度法测定痕量金 总被引:4,自引:2,他引:4
本文研究了用长光路光度法测定痕量金,采用410~#哌啶树脂富集,分离,基于溴金酸与乙基罗丹明B形成红色离子缔合物可萃取于苯中比色。该法具有高灵敏度和高稳定性。测定金的线性范围为2~60ng/ml,试用于金含量为0.46Pg/g的矿样。相对标准编差小于12.5%。 相似文献
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Gran公式已被广泛应用于离子选择性电极分析工作中。通过作图外推求得待测离子浓度。但是在处理标准加入法所得到的实验数据之前,必须预先已知电极的实际斜率值。如果以理论斜率值为基础,则必须作空白体系校正。 相似文献
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K比例H点标准加入法计算研究 总被引:6,自引:0,他引:6
为了获得在有干扰存在下的复杂体系中待测样品的准确浓度,提出了称对“K比例H点标准加入法”的方法,此方法通过在选定的两波长下样品标准加入浓度与吸收光的线性方程经K比例法消除干扰后求出其交点H(-CH,AH)则CH就是待测物的浓度,本文研究了这各的回归及H点计算的方法并给出了应用程序实例。 相似文献
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根据电极表面被测物浓度变化经验公式所建立的改进计时电流法的理论模型,只能定性分析响应电流峰值与被测物浓度关系,无法准确描述响应电流峰值与反应体系及激励电势中其它参数的关系.为解决该问题,利用能斯特方程与扩散定律,建立了描述电极表面被测物浓度与响应电流关系的积分方程,通过数值分析方法求解得到该积分方程数值解.进而利用数值仿真得到精确的电流与时间关系曲线,分析了电流峰值与试剂浓度、惯性时间常数、参比电极标准电势、激励电势初始值以及稳态值之间的关系.最后,利用改进计时电流法的电路装置对K3[Fe(CN)6]试剂进行测试,实验结果表明该数值模型比经验模型更接近真实情况,也验证了由该模型推导得到的各参数之间关系的正确性. 相似文献
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韩晓 《中国无机分析化学》2017,7(3):62-64
采用盐酸溶样,标准加入法消除基体铬的干扰,利用电感耦合等离子体原子发射光谱(ICPAES)法测定金属铬中Fe、Al、Si。对仪器参数以及被测元素的谱线选择进行了讨论,在选定最佳条件下,对标准样品金属铬进行测定,探讨了检测方法中标准曲线线性相关性、检出限、精密度及加标回收率等指标,发现各元素的测定值与认定值基本一致,测量相对标准偏差均小于1%(n=7),加标回收率在96.9%~101%。方法实用性强,已经成功应用于金属铬中杂质元素的检测。 相似文献
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《Electroanalysis》2005,17(17):1589-1594
Simultaneous determination of bismuth and copper by anodic stripping voltammetry using H‐point standard addition method (HPSAM) with simultaneous addition of analytes is described. The effect of various parameters including acid concentration, accumulation time, accumulation potential and concentration ratio of analytes in the standard solution on the sensitivity and accuracy of method were investigated. The results of applying the H‐point standard addition method showed that Cu2+ and Bi3+ could be determined simultaneously with the concentration ratios of Cu2+ to Bi3+ varying from 1 : 15 to 16 : 1 in the mixed sample. The method was successfully applied to the simultaneous determination of copper and bismuth in some synthetic mixtures. 相似文献
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Simultaneous determination of total iron and vanadium by H-point standard addition method (HPSAM) and partial least squares (PLS) is described. Gallic acid (GA) in a cationic micellar solution of CTAB was used for determination of iron and vanadium in different oxidation states at pH 5. The presence of a micellar system enables total iron and vanadium to be determined with improved sensitivities. The total relative standard error for applying the PLS method to 15 synthetic samples in the ranges 0.20–15.00 μg ml−1 iron and 0.20–8.00 μg ml−1 vanadium was 2.2%. The results of applying the H-point standard addition method showed that iron and vanadium can be determined simultaneously with the concentration ratios of iron to vanadium from 10:1 to 1:20 in the mixed sample. Both HPSAM and PLS methods showed suitable abilities to resolve accurately overlapped absorption spectra of the compounds. Both proposed methods were successfully applied to the determination of Fe and V in several synthetic alloy solutions. 相似文献
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The H‐point standard addition method (HPSAM), based on spectrophotometric measurements for simultaneous determination of phosphate and silicate, has been established. The method is based on the difference between their reactions rates with molybdenum in the presence of ascorbic acid. The results revealed that phosphate and silicate could be determined simultaneously with the concentration ratios of phosphate to silicate varying from 1:10 to 12:1 in the binary mixtures. The effects of chelating agent nature, time, interferents and experimental variables are also investigated. Under working conditions, the proposed method was successfully applied to the simultaneous determination of phosphate and silicate in synthetic detergents. 相似文献
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H-point standard addition method in the analysis by differential pulse anodic stripping voltammetry Simultaneous determination of lead and tin 总被引:1,自引:0,他引:1
The applicability of H-point standard addition method (HPSAM) to the resolving of overlapping differential pulse anodic stripping voltammetric peaks corresponding to the oxidation of lead and tin is verified. The results show that the H-point standard addition method is suitable for the simultaneous determination of lead and tin in aqueous media. The results of applying the H-point standard addition method showed that Sn2+ and Pb2+ could be determined simultaneously with the concentration ratios of Sn2+ to Pb2+ varying from 1:5 to 10:1 in the mixed sample. The proposed method has been successfully applied to the simultaneous determination of lead in the presence of tin in some synthetic samples. Moreover, the applicability of the method was demonstrated by the recovery of lead in a canned soft drink sample. 相似文献
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A simple, selective and precise voltammetric method for the determination of ascorbic acid in pharmaceutical preparations and fresh fruit juices-complex matrices containing various reducing compounds-is described. The method is based on the electrocatalytic oxidation of ascorbic acid in homogeneous solution using electrogenerated ferriciniumcarboxylic acid as mediator. The pH and mediator concentration affecting the performance of the electrocatalytic oxidation of the analyte were optimized. The method was applied to determine vitamin C in deeply coloured, viscous and turbid fruit juice samples with ascorbic acid contents ranging from 15-45 mg per 100 ml, without further dilution, concentration or other pre-treatment of the samples. The amount of mediator used varied depending on the ascorbic acid concentration in the samples. The method was also used for pharmaceutical analysis using a calibration graph. For fruit juice samples the standard addition technique was adopted to prevent the matrix affecting the accuracy of the determination. The relative standard deviation for the analysis of vitamin C in fruit juices ranged from 1.5-5%. The reliability of the method was established by parallel determination against the official methods. 相似文献
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Maryam Bordbar Ali Yeganeh-Faal Jahanbakhsh Ghasemi Mohammad Mahdi Ahari-Mostafavi Nahid Sarlak Mohammad Taghi Baharifard 《Chemical Papers》2009,63(3):336-344
A simple, sensitive and selective spectrophotometric method for simultaneous determination of tretinoin and minoxidil using
partial least square (PLS) calibration and H-point standard addition method (HPSAM) is described. The results of the H-point
standard addition method show that minoxidil and tretinoin can be determined simultaneously with the concentration ratio of
tretinoin to minoxidil varying from 2: 1 to 1: 33 in mixed samples. A partial least squares multivariate calibration method
for the analysis of binary mixtures of tretinoin and minoxidil was also developed. The total relative standard error for applying
the PLS method to eleven synthetic samples in the concentration range of 0–10 μg mL−1 tretinoin and 0–32 μg mL−1 minoxidil was 2.59 %. Both proposed methods (PLS and HPSAM) were also successfully applied in the determination of tretinoin
and minoxidil in several synthetic pharmaceutical solutions. 相似文献
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苏春风 《中国无机分析化学》2020,10(6):28-32
通过用四酸与微波消解法溶解样品对比,建立了用硝酸、盐酸、氢氟酸、高氯酸分解样品,采用电感耦合等离子体质谱法(ICP-MS)测定稀土矿中16种元素含量。方法采用103Rh作为内标消除干扰,确定了最优测定条件,16种稀土元素检出限为0.0029-0.0099ng/mL,测定范围为0.0005-0.020%。精密度试验、加标回收试验及标准物质检测,结果验证了方法的可行性及准确性。该方法简单易操作,结果可靠,能满足实验分析要求。 相似文献
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马丽 《中国无机分析化学》2013,3(3)
应用电感耦合等离子体发射光谱法测定锌精矿中的铟,确定了最佳工作条件,选择了最佳分析谱线,并利用标准加入法和基体匹配法确定了该方法的准确性。样品用氟化氢铵、盐酸、硝酸、高氯酸溶样,用盐酸浸取。本法与萃取分离盐酸羟胺示波极谱法测定的铟含量结果一致。方法准确,快速,加标回收率为99.6%~101.7%,相对标准偏差为0.97%~2.1%。 相似文献