共查询到19条相似文献,搜索用时 78 毫秒
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将测定酯化产物皂化值的吡啶/水溶剂改为正丙醇/乙二醇溶剂,克服了吡啶/水溶剂的刺激、腐蚀性,同时也改善了溶剂自身方面对测试结果带来的不利影响,提高了分析的稳定性及准确性。实践证明:正丙醇/乙二醇溶剂能完全满足测试要求,并降低了测试成本。 相似文献
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介绍了用电导滴定法测定环烷酸钴皂化值的新方法,所得电导滴定曲线线性关系良好,测定结果准确可靠。 相似文献
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对硬脂酸皂化值测定用盐酸标准溶液(0.5 mol·L-1)配制和标定过程中的不确定度来源进行分析,并对标定结果进行不确定度评估.结果表明,盐酸标准溶液不确定度的主要来源是滴定体积的不确定度分量,其中滴定管检定引入的标准不确定度分量影响最大.本方法评定的盐酸标准溶液的浓度为(0.505 0士0.001 2)mol,L-1. 相似文献
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本文分析了油脂连续高压无催化水解法生产的甘油,在其回收过程中,对其皂化值的影响因素及控制方法进行了分析。 相似文献
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Identification of Recycled Cooking Oil and Edible Oils by Iodine Determination and Carbon Isotopic Analysis 下载免费PDF全文
Hai Lu Chao Wei Hui Fu Xiuqin Li Qinghe Zhang Jun Wang 《Journal of the American Oil Chemists' Society》2015,92(11-12):1549-1553
Elemental iodine determination by ICP‐MS and carbon isotope analysis by EA‐IRMS were jointly employed to identify recycled cooking oil from edible oils. Iodine in 204 oils demonstrated that recycled cooking oils can be distinguished from soybean oil, maize oil, colza oil, peanut oil, sunflower oil and olive oil with the exception of tea oil and mixed oil. These two types of oils can be definitively distinguished from recycled cooking oil in the carbon isotope ratio analysis. It was proposed to use total iodine analysis as the primary screening method and the carbon isotope ratio measurement as a secondary method for confirmation and verification. For routine screening, threshold values of Iodine determination and δ13C measurement were determined to be 20 ng g?1 iodine and a range of ?27.3 to ?28.5 of δ13C, respectively. 相似文献
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关于植物油碘价测定法中误差的探讨 总被引:6,自引:0,他引:6
提高分析结果准确度的方法就是减少误差。本文介绍在采用GB5 5 32 - 85方法检测碘价时 ,就其测定过程中 ,配制标准溶液所引起的误差、个人操作不当所引起的误差、偶然误差 ,以及如何避免和消除所产生的误差等几个方面进行探讨 相似文献
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Assessment of Interval PLS (iPLS) Calibration for the Determination of Peroxide Value in Edible Oils 下载免费PDF全文
Xianghe Meng Qin Ye Xiaohua Nie Qiuyue Pan Lianzhou Jiang 《Journal of the American Oil Chemists' Society》2015,92(10):1405-1412
Partial least squares (PLS) is a commonly used (and sometimes misused) chemometric technique for calibrating Fourier transform infrared spectroscopy, and allows the analysis of a variety of quality parameters associated with edible oils. Peroxide value (PV) is a typical parameter of interest; however, developing a robust, optimal, and reliable calibration method can be a daunting task. This paper examines and compares the use of interval PLS as a tool to develop a PLS PV calibration method for a single‐bounce attenuated total reflectance accessory relative to full spectrum PLS and experienced PLS, making use of correlation, variance, and pure component spectra. Using mixtures of fresh and oxidized oil covering a PV range of 1–20 meq/kg, backward interval PLS could systematically produce quality calibrations without the need to resort to experienced PLS. The experienced PLS requires a degree of spectral knowledge as well as diligent and tedious spectral examination, including largely unstructured iterative calibrations and cross‐validations to improve calibration performance. The backward interval PLS is also better than the full spectrum PLS in terms of model performance. In addition, the general model developed could account for the errors caused by oil types. 相似文献
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酸值的大小能准确衡量使用中的汽轮机油质量的好坏,是油液监测中一项重要的质量指标。在使用过程中由于氧气、温度、水分、磨损产生的金属等物质的存在会让油品酸值产生很大的变化,准确快速的测定使用中的油品酸值,能够客观反映油品质量以及机器日常运行情况,具有重要意义。 相似文献
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通过对原有食用油瓶专用料进行的技术剖析,对原有配方进行重要改进。研制的新型PVC食用油瓶料具有较好的加工流动性、抗冲击性,尤其是低温抗冲击性及清模周期有了明显提高;小容积瓶(≤2.5升)抗冲击性能已基本达到PET瓶水平。 相似文献