Determination of the Hansen Solubility Parameters of Vegetable Oils,Biodiesel, Diesel,and Biodiesel–Diesel Blends

The search for alternative fuels has been gaining attention in recent decades. The replacement of fossil fuels is driven by environmental, economic, and social factors, since the whole of society is dependent on their usage; and in this context, one alternative that has been highlighted is the use of biodiesel. Biodiesel represents a renewable, biodegradable, non‐inflammable, and low toxicity alternative to diesel. In this study, the Hansen solubility parameters (HSPs) and the interaction radii (R₀) were determined for the following materials: used frying oil, coconut oil, palm oil, biodiesel from used frying oil, diesel, and biodiesel–diesel blends (B10 and B20), using 45 solvents and solvent mixtures. The values found for the solubility parameters of the used frying oil and coconut oil were very close to those found for the biodiesel; however, the biofuel showed higher solubility in polar solvents. The values of solubility parameters of diesel, B10, and B20 were similar, increasing values according to the amount (by volume) of biodiesel added to diesel fuel.     

Investigation of Heat‐Induced Degradation of Virgin Olive Oil Using Front Face Fluorescence Spectroscopy and Chemometric Analysis

A simple setup using a 365‐nm light‐emitting diode coupled to a USB spectrometer through an optical fiber, in a front‐face fluorescence configuration, was used to investigate the heat‐induced deterioration of virgin olive oil at different heating temperatures and times. The samples were heated for 30, 60, 120 and 180 min for every temperature setting of 140, 160 and 180 °C, respectively. Two important results are reported in this article. First, a neo‐formed compound around 665 nm due to the degradation of chlorophyll was observed. This new peak was attributed to pyropheophytins. The second result showed an important rise of the peak around 489 nm, which corresponded to the oxidation products. The correlation obtained between the peroxide value and the 489 nm peak using principal component analysis revealed the mechanism of the oxidation process. It further showed that the peak around 489 nm is a direct consequence of the degradation of hydroperoxide.     

红外光谱法植物油脂分析研究进展

综述了红外光谱法在植物油脂油定性识别及定量分析中的应用。介绍了红外光谱法分析植物油脂的基本原理。论述了红外光谱法在油脂理化参数的定量分析的研究进展。展望了红外光谱法在油脂检测中的应用前景。提出多种方法联合运用的检测油脂的新思路,为红外光谱法油脂快速分析检以及定性识别分析提供参考。     

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.     

Analysis of Biodiesel Feedstock Using GCMS and Unsupervised Chemometric Methods

Various biodiesel feedstocks were evaluated using gas chromatography–mass spectrometry data combined with unsupervised chemometric methods of analysis. Peak areas of the fatty acid methyl esters (FAMEs) present in the biodiesel feedstocks (soybean oil, canola oil, waste grease, animal tallow, etc.) were utilized. The importance of chromatographic parameters, such as temperature program and column polarity, was examined with respect to the clustering that was observed using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Biodiesels in this study clustered based on feedstock type regardless of temperature program or column type, as long as FAME isomers were resolved from one another. As such, the number and type of FAME components required to observe this clustering was investigated further. In general, the minor components in the sample did not provide improved clustering and thus did not need to be included. In addition, data from various temperature programs or column types were combined to yield similar clustering, showing potential versatility in analyzing similar samples across laboratories using different columns and column properties. Overall, we determined that (1) minor FAME components are non-essential for feedstock identification and (2) PCA and HCA clustering is based on feedstock, regardless of column selection, so long as resolution of FAME isomers is achieved.     

提高柴油中多环芳烃分析准确度

车用柴油中多环芳烃的分析,采用的方法是技术要求比较高的质谱法。通过对内标物、质谱的调谐以及确定合理的固相萃取条件等三个方面开展工作,寻求解决分析平行性不好的问题。经过反复、多次对实验情况进行归纳,优化调整了相关条件,有效地提高了多环芳烃的准确度,取得了较好的效果。     

近红外光谱技术及其在植物油品质分析中的应用

介绍了近红外光谱技术的原理、模型建立与评价、化学计量学方法,且着重总结了该技术在植物油分析中的应用。此技术可用于快速鉴别植物油种类,准确分析含油量和脂肪酸化学组成。目前市场上植物油出现了掺假问题,而近红外光谱技术作为一种快速、方便、绿色、非破坏性的分析技术,将会在其品质检测方面有着十分广阔的应用前景。     

Rapid Determination of Olive Oil Chlorophylls and Carotenoids by Using Visible Spectroscopy

The determination of total chlorophylls and total carotenoids in olive oil by using visible spectroscopy (VIS) is reported. The proposed technique has been compared with the determination of these pigments by near infrared spectroscopy (NIRS) and VIS together with NIRS. Several procedures for multivariate regression were tested. The reference methods used were the determination of the extinction coefficient K₆₇₀ for total chlorophylls and K₄₇₀ for total carotenoids. A total of 258 samples were tested. The optimization of the calibration for total chlorophylls was set by using multiple linear regression (MLR) from the wavelengths 670–686 nm exclusively visible. Its satisfactory performance was proven from the model coefficients standard error of calibration SEC 2.63 and R² 0.97, and the residual predictive deviation (RPD) 5.76 from the external validation. For the total carotenoids the best VIS calibration was fit by using the window of 465–475 nm and partial least squares (PLS), which provided an RPD of 3.68. However, the model built using the entire spectrum VIS‐NIRS available (350–2,500 nm) was slightly better for this last pigment, showing an RPD of 3.86. Hence, this study showed that the proposed VIS technique can be advantageous for the determination of total chlorophylls in olive oils while it is also suitable for determining total carotenoids.     

灰色关联法和主成分分析法在大庆朝阳沟油田开发中的应用

介绍了灰色关联法和主成分分析法的基本理论与思想,通过这两种方法对大庆朝阳沟油田15个区块的物性参数做定量分析,选择其中的有效厚度、孔隙度、渗透率、原油粘度、采出程度、含水率等作为评价指标,确定了影响该地区的质量评价指标的权重大小,确定综合评价分数和分类标准。结果表明,上述两种评价方法得出的结论基本一致,评价结果与实际相吻合,值得推广应用。     

Fault Detection of Non‐Linear Processes Using Kernel Independent Component Analysis

In this paper, a new non‐linear process monitoring method based on kernel independent component analysis (KICA) is developed. Its basic idea is to use KICA to extract some dominant independent components capturing non‐linearity from normal operating process data and to combine them with statistical process monitoring techniques. The proposed method is applied to the fault detection in the Tennessee Eastman process and is compared with PCA, modified ICA, and KPCA. The proposed approach effectively captures the non‐linear relationship in the process variables and showed superior fault detectability compared to other methods while attaining comparable false alarm rates.     

Analysis of Ink/Coating Penetration on Paper Surfaces by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) in Conjunction with Principal Component Analysis (PCA)

Time-of-Flight Secondary ion mass Spectrometry (ToF-SIMS), in conjunction with Principal Component Analysis (PCA), has been used to characterize the spatial distribution of the chemical components of ink, both on the surface and in the Z-direction of coated papers. Preliminary work was performed on commercial ink-jet printing paper and on commercially available photopaper to establish that ToF-SIMS, in conjunction with PCA, could help characterise ink/coating distribution. To illustrate further that ToF-SIMS/PCA could differentiate the individual components making up the ink, pigment-based and dye-based inks were applied to two coated papers (PCC + SA and PCC + starch + PVA) using an inkjet printer. This approach shows that high spatially resolved images obtained by ToF-SIMS allows a depth profile to be obtained, thereby allowing the correlation between ink distribution at the surface and in the Z-direction to be evaluated in relation to the coating formulation.     

Analysis of Ink/Coating Penetration on Paper Surfaces by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) in Conjunction with Principal Component Analysis (PCA)

Time-of-Flight Secondary ion mass Spectrometry (ToF-SIMS), in conjunction with Principal Component Analysis (PCA), has been used to characterize the spatial distribution of the chemical components of ink, both on the surface and in the Z-direction of coated papers. Preliminary work was performed on commercial ink-jet printing paper and on commercially available photopaper to establish that ToF-SIMS, in conjunction with PCA, could help characterise ink/coating distribution. To illustrate further that ToF-SIMS/PCA could differentiate the individual components making up the ink, pigment-based and dye-based inks were applied to two coated papers (PCC + SA and PCC + starch + PVA) using an inkjet printer. This approach shows that high spatially resolved images obtained by ToF-SIMS allows a depth profile to be obtained, thereby allowing the correlation between ink distribution at the surface and in the Z-direction to be evaluated in relation to the coating formulation.     

柠檬桉叶的HS-SDME-GC/MS谱图及其主成分分析

采用顶空单液滴微萃取-气相色谱/质谱法(HS-SDME-GC/MS)测定了13个不同产地的柠檬桉叶并结合主成分分析法建立判别模型,采用正交法优化其实验条件.结果表明,单液滴微萃取优化条件为:10 mL顶空瓶中1.0 g样品、60℃顶空40 min、苯甲酸乙酿吸附进而吸收柠檬桉叶中的化学物质,比对NIST 14谱库并结合...     

Polychlorinated Biphenyls in Sediments from Sicilian Coastal Area (Scoglitti) using Automated Soxhlet,GC-MS,and Principal Component Analysis

A methodology for the PAHs and PCBs congener determination in sediment samples has been revised. We determined the distributions of PAHs and PCBs in the superficial sediments of the Scoglitti (Italy) coastal area to provide data for comparison with other marine systems and to hypothesize the sources. Extraction yield, for PCB, was never less than 60% in most cases, while for PAHs, utilizing perdeuterated surrogate standard (benz[a]anthracene-d₁₂ and anthracene-d₁₀) was never less than 72%. The total concentration of the 16 PAHs investigated, expressed as the sum of concentrations, ∑PAHs, varied from 1–5087 μg/kg of dry matrix, while the ∑ PCBs ranged from detection limit to 36 μg/kg of dry matrix. Linear relationships were found between PAHs concentration and organic matter percentages (R² = 0.60) and water content and organic matter percentages (R² = 0.87). Isomeric ratios were used for discriminating between pyrolitic and petroleum origin. The principal component analysis (PCA) has been conduced to discriminate the different sampling sites in internal or external harbor area.     

Chemometric analysis of trace elements distribution in raw and thermally treated high sulphur coals

In the present study, chemometric analysis is applied as a tool to evaluate the release behaviour of trace elements (TEs) during coal utilization processes. Principal component analysis (PCA) and linear discriminant Analysis (LDA) were applied on the TE concentrations of raw and thermally treated coals. PCA and LDA successfully predicted the association of 21 trace elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sb, Te, Pb) contained in coal and their thermal behavior at various temperatures. Application of chemometric on thermally treated coals shows that at temperature 450 °C, elements like Na, P, K, Fe, Ca, Mg, Al and Si have affinity with mineral matter and therefore have low volatility. Elements like Te, Sb and Ti may form their chlorides, which enhance the volatilities of these elements, while Co and Pb may form sulfides like Co₂S₄ and PbS. In the temperature range of 600-850 °C, either coal undergones an intense degradation of its structure during pyrolysis and the elements released may be adsorbed on coal surface or be volatile. The elements Cr, Co, V, Ni may react with sulphurous gases evolved during pyrolysis. At temperature 1000 °C, wide dispersion in data elements interact with carbon and sulphur compounds of coals. The formation of compounds like Si carbide, bassanite, gehlenite, anarthite may also be responsible for low volatilities of the elements Si, Al and Ca at higher temperatures. Predictive capabilities of PCA and LDA were evaluated in terms of TEs volatilities at different temperatures. The results of chemometric analysis are not only in good agreement with volatilities of TEs present in coals at various temperatures but also with FTIR analysis.     

Discrimination of base oils and semi-products using principal component analysis and self organizing maps

¹H NMR spectroscopy, combined with pattern recognition techniques (PCA and SOM) was used in discriminating base oils and refinery-intermediate products. Both PCA and SOM enabled correct oil discrimination into groups in accordance with API 1509. Moreover, information about the structural compositions of the samples, correlated with their physical and chemical properties, was provided. The PCA score plot enabled component identification and semiquantitative analysis of binary mixtures of base oils, including semisynthetic oils.     

基于GC-MS指纹图谱和化学计量学方法鉴别陈皮

制备了陈皮挥发油提取物并建立其气相色谱-质谱（GC-MS）指纹图谱,对不同批次的陈皮指纹图谱进行相似度评价;对其共有成分峰面积数据进行主成分分析（PCA）和层次聚类分析（HCA）。建立了具有16个共有峰的新会陈皮挥发油指纹图谱,通过化学计量学分析方法能将新会陈皮和其他陈皮样品准确区分开来;不同采摘期及贮存时间陈皮的成分呈现规律性特征。方法可用于不同产地、采摘期及贮存时间陈皮的鉴别,并为陈皮的质量控制提供依据。