Authentication of Edible Vegetable Oil and Refined Recycled Cooking Oil Using a Micro-UV Spectrophotometer Based on Chemometrics

We have developed a new method to make a clear distinction between edible oil and refined recycled cooking oil by using a micro-ultraviolet spectrophotometer and analysis of spectra full data combined with principal component analysis (PCA) and cluster discriminant analysis (CDA). This method shows an excellent capability of distinguishing edible oil from refined recycled cooking oil, which is difficult to accomplish by previous methods using physical and chemical properties. Edible oils and refined recycled cooking oils have the different positions on the resulting plot of PCA and CDA. The oil samples are respectively concentrated relatively distribution and distinct from other kinds, with a certain amount of edge intersection between samples. But the edible oil and refined recycled cooking oil samples have a clear divisional interface. By the increase in sampling and the improvement of modeling, the edge intersection or overlap of commonality between samples can be reduced. Using this method, it is possible to determine qualitatively the identity of unknown samples.     

Glycerol Esters from Real Waste Cooking Oil Using a Robust Solid Acid Catalyst

Notwithstanding the food-for-fuel debate, turning waste cooking oil and fat (WCO) into a valuable product is a classic example of green chemistry. We demonstrate that sulfated zirconia and lanthanum-supported sulfated zirconia are good catalysts for the esterification of WCO free fatty acids (FFAs) with glycerol, giving high-value monoglycerides. Various catalysts were first screened using palmitic acid as a model FFA. Subsequently, six 10-kg batches of actual WCO were collected from commercial cookeries over a period of 28 weeks, pre-treated in a purpose-built decanter and esterified with industrial grade glycerol using heterogeneous catalysis. Good yield and turnovers were obtained. The pre-treatment stage and the catalytic esterification experiments are described and discussed.     

Glycerol Esters from Real Waste Cooking Oil Using a Robust Solid Acid Catalyst

Notwithstanding the food-for-fuel debate, turning waste cooking oil and fat (WCO) into a valuable product is a classic example of green chemistry. We demonstrate that sulfated zirconia and lanthanum-supported sulfated zirconia are good catalysts for the esterification of WCO free fatty acids (FFAs) with glycerol, giving high-value monoglycerides. Various catalysts were first screened using palmitic acid as a model FFA. Subsequently, six 10-kg batches of actual WCO were collected from commercial cookeries over a period of 28 weeks, pre-treated in a purpose-built decanter and esterified with industrial grade glycerol using heterogeneous catalysis. Good yield and turnovers were obtained. The pre-treatment stage and the catalytic esterification experiments are described and discussed.

     

Simple Wet Rendering Method for Extraction of Prime Quality Oil from Skipjack Tuna Eyeballs

Oil from skipjack tuna (ST) eyeballs is extracted by the wet rendering method at 121 °C for different holding times (5–60 min) using an autoclave. Yield increases as heating time increases up to 20 min (p < 0.05); no further increase is obtained with a longer heating time (p > 0.05). Conversely, acid value and total polar compounds increase. However, peroxide value (PV), thiobarbituric acid reactive substances, and anisidine value (AnV) decrease up to 30 min. No changes in unsaponifiable matter (UM) or conjugated diene (CD) are attained, regardless of heating time. Polar components (PC) increase with heating time (p < 0.05). All oil samples have a high polyunsaturated fatty acids (PUFA) content (40.46–41.00%), with monounsaturated fatty acids (MUFA) and saturated fatty acids (SFA) in the range of 20.94–21.26% and 37.77–38.45%, respectively. PUFA content is reduced slightly with a heating time of 60 min. Docosahexaenoic acid (DHA) (C22:6, n3) is the dominant fatty acid in all samples (31.67–32.24%). Based on FTIR spectra, heating for longer time results in lower intensity at wavenumbers of 3015 and 1740 cm^?1. Thus, light yellow oil from ST eyeballs prepared by a green process for an appropriate time can serve as an excellent source of DHA and other PUFA. Practical Applications: Tuna oil is known to be a rich source of DHA and PUFA with health benefits. However, precooked tuna heads, generally used as raw material, yield oils with a very dark color and offensive odor, which require several refinery processes. To reduce the number of steps in the refinery process, tuna eyeballs which are separated from tuna heads can render higher quality fish oil. Moreover, the wet rendering process, a green process without toxic substances, can be used without causing environmental problems.     

润滑剂质量简易鉴别方法

润滑剂的质量鉴别具有重要的现实意义,文章简述了润滑油和润滑脂的变质特征,并对它们的质量简易鉴别方法进行了综述。     

TOPSIS法在地表水体环境质量评价中的实践

文章介绍了目前水环境的状况及水环境质量评价的紧迫性,并且从众多评价方法中选择了TOPSIS水环境评价方法,介绍了它的原理及评价步骤,并且用它对开封市化肥河2001～2005年的水环境质量状况进行了评价,建立了评价模型。最后通过计算比较得出了与实际相符合的结果。这条河流的水为劣V类,富含大量的重金属,但是水质有逐年转好的趋势,这说明近几年开封市政府及环保局在这方面做出了一定的努力。另外分析了TOPSIS这种评价方法的优缺点并提出了改进方法。     

Improving Waste Cooking Oil Quality for Biodiesel Production with the Ethanolic By-product of Soybean Oil Extraction

Waste cooking oils (WCO) can be used as feedstock for biodiesel (fatty acid ethyl or methyl esters—FAEE or FAME) production. Their usual high acidity, high moisture, and low stability can impair the reaction yield and generate a low-quality biodiesel. Here, we performed liquid–liquid washings using WCO and ethanol-based solvents with the goal of generating oil-rich miscella as FAEE feedstocks with a higher quality than WCO. Three different solvents were evaluated: 99% ethanol, 95% ethanol, and the soybean oil extraction ethanolic phase (SEP), a by-product with immense unexplored antioxidant potential obtained by extracting soybean oil using ethanol. Washings were performed in a 1000 mL flat-bottom flask at 78.1 °C, using a 1:2 (w/v) oil/solvent ratio, under magnetic stirring (1200 rpm) for 10 min. Ethyl esters were prepared via homogeneous alkali transesterification using WCO and oil-rich miscella as feedstocks. Treatments reduced the acid value by 40–61% and the peroxide value by 15–50%. Improvements in feedstock quality generated 24–54% higher biodiesel yields. The oil-rich phase produced with SEP was 15% more resistant to oxidation than WCO. This was attributed to the transference of isoflavones from the SEP. However, biodiesel from treated samples presented equal or lower oxidative stability than FAEE from WCO. High-performance liquid chromatography (HPLC) analysis showed that no isoflavones remained in biodiesel after purification. Pretreatment of WCO with ethanol-based extracts such as the SEP has great potential to improve WCO quality for biodiesel production as it can be a source of plant-based antioxidants.     

Single Soybean Seed NMR Calibration for Oil Measurement Using Commercial Cooking Oils

Development of high oil soybeans would reduce the cost of soybean oil production for biodiesel or edible oil applications. An accurate determination of soybean seed oil concentration is essential especially when developing superior cultivars with increased seed oil content. The objective of this study was to develop an oil measurement method for single seeds using NMR spectrometry. An NMR spectrometer was calibrated using commercial cooking oil. Fifteen cultivars of known mean oil content were used to evaluate the calibration curves. The calibration curves developed had a correlation coefficient of 0.99. It was found that soybean and corn oil gave identical results over the calibrated interval.     

分光光度法测定中吸收池的正确使用与维护

介绍了吸收池的正确使用与维护方法，对吸收池的正确洗涤及检验方法做了重点介绍。     

化学镀钴液中钴(Ⅲ)的分光光度测定

研究了钴（Ⅲ）－１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）及溴化十六烷基三甲铵（ＣＴＭＡＢ）体系测定钴。钴与ＰＡＮ二元配合物摩尔吸光系数可达９４～１０３Ｌ·ｍｏｌ－１·ｃｍ－１，加入表面活性剂后，钴与ＰＡＮ生成三元配合物，摩尔吸光系数值提高到２１２～１０４Ｌ·ｍｏｌ－１·ｃｍ－１，钴含量在０～２５μｇ／５０ｍｌ范围内符合比耳定律，方法应用于测定化学镀钴液中钴的测定。     

Effect of Water on the Ethanolysis of Waste Cooking Soybean Oil Using a Tin(II) Chloride Catalyst

Biodiesel production from cheap lipid raw materials is economically welcome, but a high free fatty acids (FFA) content makes it incompatible with traditional alkaline catalysts. Although liquid mineral acids are alternatively used, serious drawbacks such as high corrosiveness and large effluent generation, as well as the impossibility of catalyst reuse compromises its application. Contrarily, solid acid catalysts appear to be an attractive option; however, the water present or generated during FFA esterification provokes the leaching and deactivation of these catalysts. Thus, in this work we have evaluated the use of tin chloride SnCl₂, which is less corrosive, water tolerant, and a recyclable Lewis acid catalyst, on FFA ethanolysis using waste cooking oil samples (WCO). Additionally, the main kinetic parameters of the reactions were assessed. Compared to pTSA (p-toluenesulfonic-acid), a catalyst also evaluated, SnCl₂ efficiently promoted FFA ethanolysis even in the presence of high amounts of water (ca. 0.1–5.0% w/w). Moreover, the homogeneous SnCl₂ catalyst was easily recovered and reused successively, without loss of activity.     

吡啶-吡唑啉酮分光光度法测定土壤中的氰化物

土壤样品在乙酸锌和酒石酸介质中蒸馏,用10g/L氢氧化钠溶液吸收蒸馏出来的氰化物,然后用具有较高灵敏度的吡啶-吡唑啉酮分光光度法测定。本方法最低检测量为0.05μg,具有灵敏度高、精密度好的特点,结果令人满意。     

Grape Seed Oil Characterization: A Novel Approach for Oil Quality Assessment

The amount of organic pomace, left behind agricultural processes, is continuously rising in accordance with industrial progress. Grape pomace, generated in the wine industry all over the world, represents a raw material for obtaining valuable products. Grape seeds are especially rich in oil containing bioactive compounds that can have various health‐related effects. The aim of the study is to compare the quality of seed oils obtained from six white grapes, including two Serbian autochthonous varieties. Linoleic acid, associated with numerous health benefits, is the major fatty acid in all samples (≈66% of total); α‐tocopherol is the main tocopherol homologue. Total polyphenol content ranges from 73.4 to 104.3 mg of gallic acid equivalents per 100 g. In order to provide comprehensive information about antioxidant capacity of grape seed oil (GSO), three tests are performed (ferric ion reducing antioxidant power; 2,2’‐diphenyl‐1‐picrylhydrazyl, and 2,2’‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid) radical scavenging). Antimicrobial activity is investigated against different strains; however, GSO inhibits the growth of Staphylococcus aureus and Candida albicans. Obtained results are used to develop a novel approach for oil quality assessment. Calculated oil quality scores (OQS) reveal no significant difference between international and autochthonous varieties, although Smederevka stands out as the most potent one. Practical applications : Considering the progressive waste increase in the wine industry and keeping in mind all health‐promoting effects of grape seed oil (GSO), it is clearly observed that oil production represents a profitable and sustainable utilization of grape seeds. The results of the present study show that GSO is a rich source of compounds with antioxidant and antimicrobial properties. In addition, this work provides deeper insight into a quality of Serbian autochthonous grape varieties that are still insufficiently explored. Furthermore, the proposed oil quality score could be used as a comprehensive and unbiased method that enables quality assessment of oils. This tool can find practical application in comparing different plant oils regarding their compositional and functional properties. Finally, it would contribute to making some general oil intake recommendations.     

Synthesis of Zinc Oxide Nanostructures with Controlled Morphologies Using a Simple Sonochemical Method

Zinc oxide (ZnO) nanostructures were synthesized by a simple sonochemical method without the assistance of an additional surfactant. The morphologies can simply be controlled only by changing the addition sequence of NH₃·H₂O. When NH₃·H₂O was added before or at the beginning of the ultrasonic treatment, a flower-like nanostructure and ellipsoidal particles self-assembled by nanorods were obtained, respectively. The strong visible emission implied high atomic defects. The emission intensity was dependent on the addition sequence of NH₃·H₂O greatly.     

肯特评分法在输油管道风险评价中的应用及改进

介绍了肯特评分法及其评价步骤,利用肯特法吴起-延炼原油管输工程进行了风险评价.通过对肯特模型计算方法中风险分值换算的改进,使相对风险值处于0～100分的范围,且改进公式表示分值越大、风险越高,易于理解,适合我国输油管道的实际情况.应用实例表明,改进公式和原有模型评价结果一致.     

Optimization of the Biocatalysis for D-DIBOA Synthesis Using a Quick and Sensitive New Spectrophotometric Quantification Method

D-DIBOA (4-hydroxy-(2H)-1,4-benzoxazin-3-(4H)-one) is an allelopathic-derived compound with interesting herbicidal, fungicidal, and insecticide properties whose production has been successfully achieved by biocatalysis using a genetically engineered Escherichia coli strain. However, improvement and scaling-up of this process are hampered by the current methodology for D-DIBOA quantification, which is based on high-performance liquid chromatographic (HPLC), a time-consuming technique that requires expensive equipment and the use of environmentally unsafe solvents. In this work, we established and validated a rapid, simple, and sensitive spectrophotometric method for the quantification of the D-DIBOA produced by whole-cell biocatalysis, with limits of detection and quantification of 0.0165 and 0.0501 µmol·mL⁻¹ respectively. This analysis takes place in only a few seconds and can be carried out using 100 µL of the sample in a microtiter plate reader. We performed several whole-cell biocatalysis strategies to optimize the process by monitoring D-DIBOA production every hour to keep control of both precursor and D-DIBOA concentrations in the bioreactor. These experiments allowed increasing the D-DIBOA production from the previously reported 5.01 mM up to 7.17 mM (43% increase). This methodology will facilitate processes such as the optimization of the biocatalyst, the scaling up, and the downstream purification.     

微乳液介质-水杨基荧光酮光度法测定石油中微量铜

以微乳液[v(正丁醇)∶v(正庚烷)∶v(乳化剂OP)∶v(水)=1∶1∶18∶80)为介质,水杨基荧光酮为显色剂,三乙醇胺为掩蔽剂,在混合磷酸盐(磷酸二氢钾-磷酸氢二钠)缓冲体系中,采用分光光度法,直接测定油样中的微量铜,铜的显色络合物的最大吸收波长位于600 nm处。该方法灵敏度高、准确性和精密度好,且操作简单易行、经济实用,对环境污染小,具有一定的实际意义。     

浅析建设单位工程质量的控制方法

为确保在施工程质量受控,施工过程满足国家现行的施工规范和质量标准,实现合同约定的工程质量目标,工程各参与方对工程质量均有着管理义务。本文从房地产开发单位角度,讨论工程质量控制工作中其应完成的一些重要工作。     

一种简易脱除焦化柴油中碱性氮化合物的方法

用二氧化碳酸性水溶液洗涤焦化柴油，使油中的碱氮化合物溶于水，从而将碱氮从焦化柴油中分离出来。实验结果表明，大庆焦化柴油经此种方法洗涤后，可脱除碱氮约６０％。此方法工艺简单、投资少、成本低，目前可以作为加氢精制的预处理手段。