糕点水分含量对脂肪测定值的影响——GB5009．6—2003中样品处理方式对脂肪含量测定影响的分析

糕点类食品是一种富含热量，比较方便实惠的食品，是人们日常需要的、比较喜欢吃的食品之一，尤为儿童和老年人喜欢。它主要是以小麦粉、食糖、油脂、蛋品、乳品及其它辅料为原料，经和面、焙烤、蒸、炸等加工工艺制成的各种糕点。糕点类食品营养丰富，     

浅谈糕点中水分的测定

本文介绍了糕点中水分的测定方法——重量法中的常压干燥法。     

离子色谱法对糕点中丙酸钙的测定

本文采用抑制型电导检测器建立了离子色谱法测定糕点中丙酸钙含量的方法。糕点经蒸馏、提取、过滤后,用Dionex Ion Pac ASl9(4×250mm)分离柱分离,以RFC-30淋洗液自动发生器产生的5 mmol KOH为淋洗液,流速1.0ml/min,经抑制电导检测器检测。该方法在0.10～20.0mg/L范围内线性关系良好,检出限达0.02 mg/L。该方法稳定,重现性好,保留时间相对标准偏差RSD(n=7)为0.18%,峰面积RSD(n=7)为1.15%。将该方法用于糕点实际样品的测定,回收率为91.77%,结果良好。     

索氏抽提法测定食品中脂肪含量方法改进研究

本文对《食品中脂肪的测定》索氏抽提法的实验技术进行了改进技术措施,并运用这些方法,选取黑芝麻、黄豆、花生仁、核桃仁、香肠、猪肉干、牛肉干、方便面八个样品并进行脂肪含量测定,提高了测定准确度和重复性,结果满意。表明改进后的方法实用性强,实验操作更为科学合理,以确保获得高质量的检测结果。     

水分含量对改性铵油炸药性能的影响

从水分含量对改性铵油炸药的爆炸性能和贮存期的影响进行了研究。发现水分含量为0.04%～0.20%范围内,对改性铵油炸药的爆速和殉爆距离具有明显影响;在水分含量不大于0.07%的情况下,改性铵油炸药在其贮存期内的爆速及殉爆距离能满足一般工程应用的要求。综合考虑水分对改性铵油炸药爆炸性能及贮存稳定性的影响,水分含量以不大于0.04%为宜。     

水分含量对改性铵油炸药性能的影响

从水分含量对改性铵油炸药的爆炸性能和贮存期的影响进行了研究。发现水分含量为0.04%～0.20%范围内,对改性铵油炸药的爆速和殉爆距离具有明显影响;在水分含量不大于0.07%的情况下,改性铵油炸药在其贮存期内的爆速及殉爆距离能满足一般工程应用的要求。综合考虑水分对改性铵油炸药爆炸性能及贮存稳定性的影响,水分含量以不大于0.04%为宜。     

糕点中总糖含量测定的不确定度评定

利用斐林氏容量法对糕点中总糖含量进行了测定,依据《JJF 1059.1-2012测量不确定度评定与表示》,对测定结果进行不确定度分析与评定。通过不确定度分析,找出影响总糖测定过程中不确定度的主要来源,从而对检测过程中易引入较高不确定度的环节加以控制,确保检测过程和结果的可靠性。     

电子秤不能准确反映人体脂肪含量

在德国．既能显示体重又显示体内脂肪含量的电子秤很受欢迎。但德国科学家最近却发现，这种电子秤显示的人体脂肪结果并不准确，相反，这一结果很大程度上是指人体水分的含量。     

Metrologically Traceable Determination of the Water Content in Biopolymers: INRiM Activity

Water content in materials is a key factor affecting many chemical and physical properties. In polymers of biological origin, it influences their stability and mechanical properties as well as their biodegradability. The present work describes the activity carried out at INRiM on the determination of water content in samples of a commercial starch-derived biopolymer widely used in shopping bags (Mater-Bi\(^{\circledR })\). Its water content, together with temperature, is the most influencing parameter affecting its biodegradability, because of the considerable impact on the microbial activity which is responsible for the biopolymer degradation in the environment. The main scope of the work was the establishment of a metrologically traceable procedure for the determination of water content by using two electrochemical methods, namely coulometric Karl Fischer (cKF) titration and evolved water vapour (EWV) analysis. The obtained results are presented. The most significant operational parameters were considered, and a particular attention was devoted to the establishment of metrological traceability of the measurement results by using appropriate calibration procedures, calibrated standards and suitable certified reference materials. Sample homogeneity and oven-drying temperature were found to be the most important influence quantities in the whole water content measurement process. The results of the two methods were in agreement within the stated uncertainties. Further development is foreseen for the application of cKF and EWV to other polymers.     

养殖水中油类含量的苯乙烯示值法研究

根据芳烃类与稠环共轭双键化合物有紫外吸收这一特点,提出以相对于苯乙烯含量为水中油类含量的示值,表示油类总量。此法简便、易行,且结果具有相对稳定性和可对比性。     

硝酸铵水分含量对粉状硝铵炸药质量的影响

文章详细论述了在生产工艺及原辅材料配比相同的情况下,硝酸铵含水量高低对粉状炸药的殉爆距离、爆速影响至关重要,提出了解决的方法,使产品质量得到了稳定提高.     

彩色显影液冲洗水中CD-3、CD-4含量的测定

Ｃ Ｄ３ 或 Ｃ Ｄ４ 的氧化物能与１６９ 成色剂偶合成品红染料，本文阐述了用分光光度法来测定彩色显影液冲洗水中 Ｃ Ｄ３ 或 Ｃ Ｄ４ 的含量。     

卡尔·费休法测定乳化炸药含水量

文章对乳化炸药中水分的存在形式进行了分析,并提出了一种适用于乳化炸药含水量的测定方法——卡尔·费休水分测定法。经过测定不同生产工艺、不同乳化剂的乳化炸药样品的含水量,并作重现性试验和回收试验,表明该方法在测量乳化炸药含水量时,具有测量时间短、精度高、测量结果重现性好等特点,适合在生产线或实验室进行推广应用。     

高效液相色谱法测定月饼中防腐剂的方法研究

本文研究建立了一种对月饼中苯甲酸、山梨酸和脱氢乙酸的检测方法.样品经氢氧化钠浸泡,超声提取,沉淀蛋白质后,直接进高效液相色谱仪测定,三种防腐剂成分的回收率在98.8%～101.0%之间.该法测定结果准确,操作简便,结果令人满意.     

添加剂对煤沥青在喹啉不溶物滤饼中渗透性的影响

本工作研究了添加剂对煤沥青的渗透性的影响.本研究采用的添加剂是阳离子型和非离子型添加剂的混合体系.它们对煤沥青的粘度和组成的影响很小,但是渗透性却有大幅度提高,根据达西定律和渗透系数方程对煤沥青浸渍动力学进行了讨论,认为添加剂起到了凝聚QI颗粒、增大有效尺寸和增大孔隙率的作用,改变了滤饼结构.随着其含量的增加,渗透性呈现先增加后减小的规律.通过对2D炭预制体致密化发现,添加剂能够提高煤沥青对高密度的预制体的致密化效率.     

Effect of Residual Water Content on the Physico-Chemical Properties of Sucralfate Dried Gel Obtained by Microwave Drying

The purpose of this study was to investigate the physico-chemical characteristics of sucralfate humid gel dried by microwaves, in relation to the residual water content. Differential scanning calorimetry (DSC) allowed for the determination of the water state in sucralfate samples. Fourier-transform infrared (FT-IR) spectroscopy was used to monitor the changes in sucralfate gel structure induced by the microwave drying. A boundary value of total water content for sucralfate gel samples was found at 42% (w/w). Below this value only bound water was present, whereas above this value, the increase in total water was due to free water. In the physical form of gel, the strength of the coordination between sulfate anions and the positively charged aluminum hydroxide was dependent on the residual water content. The study of the sedimentation behavior of water suspensions prepared with dried sucralfate allowed for the evaluation of the retention of gel properties. We found that the microwave drying process affected the sedimentation of sucralfate dried gel suspensions independent of the residual water content: when suspensions were prepared from sucralfate dried gel powders containing more than 42% (w/w) of residual water, the sedimentation ratio was higher than 0.9. The non-gel powder suspension showed a sedimentation ratio of 0.68 ± 0.02, whereas the sucralfate humid gel suspension did not sediment.     

地表水中叶绿素a的测定

在生产力叶绿素a测定方法中,对叶绿素a提取、提取液保存时间、滤膜对样品影响等进行比较实验,并提出了改进建议。