A conversion factor to determine phospholipid content in soybean and sunflower crude oils

The major phospholipids (PL) from soybeans and sunflowers were separated by 2-dimensional thin layer chromatography (TLC) and the fatty acid composition of each PL was determined by gas liquid chromatography (GLC). PL from soybeans and sunflowers contained high percentages of linoleic and palmitic acids. Only phosphatidylinositol (PI) from both oilseeds were similar in fatty acid composition and the principal acid was palmitic acid. Sunflower phospholipids, except for PI, contained twice as much oleic acid as did those from soybeans. Sunflower PI contained very low but measurable quantities of heptadecanoic acid. The molecular weights (MW) of individual PL were based on their fatty acid composition. The MW found for soybeans and sunflower PL were quite similar even though their fatty acid compositions were different. The average MW of PL in crude soybean and sunflower oils was determined based on the MW of individual PL and their composition in the PL fraction. From that MW, a factor for converting phosphorous content in oil to its PL content was calculated. For both oils, the factor was 25.     

An investigation of oven methods for determining the moisture content of shelled peanuts

Air-oven methods, using ground, sliced, and whele shelled peanuts, were investigated. The use of ground samples was found to be unsatisfactory. Slightly more accurate results were obtained with whole nuts than with sliced nuts. The method of heating 50-g. samples of whole shelled peanuts for 3 hrs. at 130°C. in a foreed-draft oven gave results agreeing closely with those obtained by the Karl Fischer method for samples of low moisture content.     

A method to determine the monoglyceride content in fats and oils

A methodology was worked out to analyze monoglycerides present in fats and oils in low levels (<0.5%). The monoglycerides are enriched by acetonitrile extraction and further evaluated either by gas liquid chromatography or by a combination of thin layer chromatography-gas liquid chromatography. Results are presented showing the selectivity, yield, and reproducibility of the isolation step and the efficiency of the thin layer chromatography fractionation. Examples also are given demonstrating some possible applications of the proposed method.     

A method for determining kernel moisture content and aflatoxin concentrations in peanuts

A method was developed to determine kernel moisture content (KMC) and aflatoxin concentration in discrete peanut samples. Shelled peanuts were weighed to the nearest 0.01 g, and a water slurry was made by blending the peanuts for 2 min with 2.2 ml of water per g of peanuts. The slurry (10 g) was withdrawn and dried at 130°C for 3 h to determine KMC. Methanol was added to the remaining slurry and blended for an additional 1 min, and aflatoxins were quantitated with high-performance liquid chromatography. Comparison of the slurry method with an official peanut moisture method showed good agreement between the two over a range of moisture levels. Recovery of aflatoxin B₁ from spiked samples averaged 97% with an average coefficient of variation of 3.6%. The method enables determination of both KMC and aflatoxin content in peanut samples without degradation of aflatoxin that would occur when using the official moisture method.     

Control of the hydrocellulose film drying process using a rapid method of moisture content determination

Conclusions A quick-method of determining the moisture content of hydrocellulose film has been developed, which makes it possible to carry out measurements in 10–15 min, with a meansquared error of ±0.4% (absolute).A method has been suggested for calculating corrections for moisture exchange of a specimen with the surrounding medium during the time of withdrawing it; it offers the possibility of determining moisture content of the film in a roll.A system for stabilizing the moisture content of film has been included in the composition of the automatic control system for cellophane manufacture at the Kiev Khimvolokno PO.Translated from Khimicheskie Volokna, No. 2, pp. 57–59, March–April, 1988.     

磷矿石中氧化铝含量测定方法优化

偏铝酸盐分离-EDTA容量法测定磷矿样品氧化铝含量,熔样和杂质分离一次完成,操作方法简单,分离效果好,但熔样过程难以精准控制,进而导致测定结果不稳定。对熔样操作步骤进行优化后,测定误差小,能更准确地分析磷矿样品中氧化铝的含量,有效提高分析质量,为磷矿有效综合利用提供准确的基础数据。     

一种基于温度参量的西林瓶内氧气浓度检测方法

目前西林瓶内氧气浓度多采用离线抽样破坏性检测,存在耗时长、精度低、漏检率高等不足。应用可调谐半导体激光吸收光谱（TDLAS）理论,构建氧气浓度与温度、二次谐波强度之间的理论关系模型,提出一种利用温度参量在线检测瓶内氧气浓度的方法。详细阐述了实验设计方法和步骤,优化了最佳入射角和系统主要参数,在气体压强为1atm（101.325 kPa）和温度为296 K的条件下,采集不同氧气浓度的西林瓶作为初始建模样本,建立常规的氧气浓度反演模型。同时样本浓度为21%的西林瓶所对应的二次谐波幅度,作为基于温度参量来定量预测的参考幅度。实验结果表明,利用温度参量检测瓶内氧气浓度能有效克服温度大幅变化对浓度反演的直接影响,预测的均方根误差（RMSEP）相对直接浓度反演预测降低了80.33%。     

简便测定L-半胱氨酸含量的方法

目前有22种氨基酸可由发酵法制得,只有胱氨酸和L-半胱氨酸不能用发酵法生产.而L-半胱氨酸可由胱氨酸还原而来,其化学反应式为:     

A new method to determine swelling pressure

A new method for the determination of the swelling pressure π_s of gels is presented. The gel remains in the isotropic state when the isothermal mechanical equilibrium is established. The temperature dependence of π_s can be measured at constant composition. The applicability of the method is demonstrated for chemically crosslinked gelatine swollen in water.     

气相色谱法测定水泥助磨剂中三异丙醇胺含量

采用气相色谱法测定工业用品中三异丙醇胺含量的方法来测定水泥助磨剂中的三异丙醇胺含量。结果表明,该方法准确、可靠,操作简单方便。     

Assessment of the initial moisture content on soybean drying kinetics and transport properties

Several researchers have developed studies to obtain a mathematical model able to describe grain drying kinetics. However, most of these studies neglect the effect of grain initial moisture content on drying curves. In this study, we assessed the dependence of drying curves and mass transfer coefficients on this initial moisture, air temperature, and its velocity by measuring grain mass losses within time on a tray dryer. Mathematical models were adjusted and results indicated that initial grain moisture content has significant influence on drying curves and mass transfer coefficients.     

应用低水分熄焦工艺改造焦炉熄焦系统

低水分熄焦工艺具有熄焦均匀、焦炭整粒、改善环境及延长设备寿命等诸多优点。文中介绍了低水分熄焦工艺的先进性与可实施性,并根据本钢焦化厂实际情况,将低水分熄焦工艺用于原湿法熄焦工艺的改造,设备选型全部国产化。改造后焦炭水分指标由改造前的平均5.3%下降到4.4%,熄焦操作时间由原160s缩短为70s。     

The use of oven heat sag to determine heat resistance in polypropylenes

Heat deflection is often the only test used to determine a materials ability to withstand exposure to elevated temperatures under load. This test has its limitations, simply because not all materials operate under loads of 1820 kPa (264 psi) or 455 kPa (66 psi). Consequently, heat deflection cannot always give a true indication of a materials high temperature capabilities. The automotive industry has used the heat sag test to measure the deformation of elastomeric materials during the paint curing process. The heat sag test measures the sag of a molded bar. One end of the bar is clamped while the other end is free to sag or deflect. Samples are tested over a range of temperatures to determine the failure deflection point. This study examines the correlation of the heat sag to heat deflection and dynamic mechanical analysis (DMA) on polypropylene resins and compounds and polystyrene.     

甲醛——电导法测定工业废水中NH4^＋离子的含量

用甲醛与工业废水中ＮＨ４＾＋定量反应释放出Ｈ＾＋,用电导率仪测量电导率变化值,通过工作曲线求出工业废水中ＮＨ４＾＋的含量。此法回收率９９．２％￣１００．８％对化工厂排放的废水进行水样分析,并与蒸馏法进行比较,相对标准偏差ＣＶ＝０．５％￣０．５９％,蒸馏法相对标准偏差ＣＶ＝０．６１３％￣０．１４４％。此法快速,设备简单,操作方便,准确度高,重现性好,不爱其它离子干扰,适合化工厂和环境监测。     

A rapid method of determining the moisture content of hydrocellulose films and casings

Translated from Khimicheskie Volokna, No. 6, pp. 54–55, November–December, 1991.