一种基于简化机理模型的线性扫描极谱波

针对线性扫描极谱法在线同时分析湿法炼锌浸出液中多金属组分时亟待解决的重叠峰分离难题,提出了一种新的分离此类重叠峰的方法。通过深入研究极谱波的产生机理,采用非线性加权最小二乘法对重叠峰进行拟合,获得待分离峰重构参数的精确值,并以此重构参数为基础,将重叠峰分离为独立子峰。实验结果表明,该极谱波模型具有很好的极谱峰描述能力与准确的分辨能力,能够快速,准确的实现极谱重叠峰分离。     

免疫算法在重叠拉曼谱峰中的应用

拉曼光谱及其联用技术的快速发展使其成为复杂样品分析的重要手段,但由于环境的复杂性以及拉曼光谱信号的特点,在复杂样品分析中难免会出现一些重叠谱峰。为此,采用小波变换扣除原始信号中的荧光背景得到有用信号,并基于免疫算法将该方法对重叠拉曼光谱谱峰信号进行解析。结果表明：该方法可以准确地将重叠拉曼光谱谱峰信号进行分离,并且同时得到了各组分的定量信息,绝对误差在2%之内。     

拟合模型对PA66/PET合金峰分离结果的影响探讨

采用转矩流变仪制备了不同质量比的聚酰胺66/聚对苯二甲酸乙二醇酯(PA66/PET)合金,并进行了差示扫描量热(DSC)测试,通过耐驰峰分离软件将测得的DSC曲线中2组分重叠的熔融峰进行准确地分离,同时能够输出分离后各单峰熔融温度、峰面积及占重叠峰面积的百分比等有价值信息,探讨了5种不同的数学拟合模型的分离效果。结果表明,选用Fraser-Suzuki分布模型进行计算处理,拟合后的曲线与原始曲线重合度最高,得到的相关系数最高,平均拟合误差最小。     

计算复杂穆斯堡尔谱的一个方法

本文阐述了一个计算复杂穆斯堡尔谱方法的主要思想,它是高斯-牛顿法的一种改进,计算实践表明,它对分开较多的吸收峰及重叠峰是有效的.     

六种苯并咪唑化合物的NMR分析

苯并咪唑化合物是苯环与咪唑环相连构成的具有生物活性的化合物,含这类结构的化合物具有杀菌、杀虫等作用,广泛应用于医药化工产品中。其结构中质子数量少且化学环境相似,核磁共振(NMR)氢谱芳香区易出现谱峰重叠,不利于质子化学位移指认。~(13)C核性质较稳定,测量精度较高,谱图化学位移值范围较大,不易发生谱峰重叠。本文通过~1H NMR、~(13)C NMR、ROESY、HSQC、HMBC对谱峰重叠严重质子的化学位移进行区分,准确归属~1H、~(13)C核的化学位移。     

GC/MS/DRS在香精香料定性分析中的应用

为探索解卷积报告软件(DRS)在香精香料分析中的应用,选用纯香精及成品提取香精为代表样品,利用DRS软件对香精香料进行检索分析,结果表明DRS可以自动识别重叠的色谱峰并将其与目标谱库进行匹配,为重叠峰的定性提供了直观的鉴别依据。     

4,6-二正丁氧基-1,3-二-(4-烯丙基-2-甲氧基)苯二磺酸酯对金属离子的识别作用

利用紫外光谱分析的方法研究了4,6-二正丁氧基-1,3-二-(4-烯丙基-2-甲氧基)苯二磺酸酯对Ca2+、Pb2+及部分过渡金属等20种金属离子的识别。结果发现,化合物对Bi3+显示出较好的选择性,在化合物-Bi3+的体系中加入Sn2+或Cu2+,由于Sn2+(或Cu2+)和Bi3+协同作用的影响,紫外吸收光谱290³00 nm处的吸收峰红移至313300 nm处的吸收峰红移至313³22 nm,并且随Sn2+(或Cu2+)浓度的增大峰发生红移,峰强度逐渐增强。     

4,6-二正丁氧基-1,3-二-(4-烯丙基-2-甲氧基)苯二磺酸酯对金属离子的识别作用

利用紫外光谱分析的方法研究了4,6-二正丁氧基-1,3-二-(4-烯丙基-2-甲氧基)苯二磺酸酯对Ca2+、Pb2+及部分过渡金属等20种金属离子的识别。结果发现,化合物对Bi3+显示出较好的选择性,在化合物-Bi3+的体系中加入Sn2+或Cu2+,由于Sn2+(或Cu2+)和Bi3+协同作用的影响,紫外吸收光谱290~300 nm处的吸收峰红移至313~322 nm,并且随Sn2+(或Cu2+)浓度的增大峰发生红移,峰强度逐渐增强。     

电荷补偿对ZnO:Eu~(3+)材料荧光性能的影响(英文)

采用机械力固相化学反应法制备了含3%Eu3+(摩尔分数,下同)ZnO:Eu3+(ZnO:3%Eu3+)发光材料,研究了ZnO:3%Eu3+发光材料的激发与发射光谱,以发射光谱的主峰(λem=611nm)作为监控波长,其激发光谱的主峰对应λem=465nm,分析了ZnO:3%Eu3+材料的发射峰强度随电荷补偿剂Li+,Na+和K+掺杂浓度的变化规律。结果表明:随电荷补偿剂含量增大,ZnO:Eu3+材料的发射峰强度均出现先增大后减小趋势,但在不同电荷补偿剂下,ZnO:Eu3+材料的发射峰强度最大处对应的电荷补偿剂含量不同,此时对应的Li+,Na+和K+的摩尔分数分别为1%,0.75%和0.70%。     

微生物浸出MnO_2过程中嗜酸氧化亚铁硫杆菌与Fe~(3+)的催化作用

考察了MnO2-FeS2-H2SO4细菌浸出体系下,嗜酸氧化亚铁硫杆菌和Fe3+单独或联合对MnO2浸出Mn2+的浸出速率影响,并采用循环伏安电化学方法对过程中嗜酸氧化亚铁硫杆菌与Fe3+的催化作用进行了分析。结果表明:嗜酸氧化亚铁硫杆菌和Fe3+单独或联合都可以有效提高MnO2浸出Mn2+的浸出速率,对MnO2细菌浸出过程有一定催化作用;循环伏安电化学分析表明嗜酸氧化亚铁硫杆菌和Fe3+单独或联合加入,都会使FeS2出现明显的氧化还原峰,且嗜酸氧化亚铁硫杆菌可以降低FeS2的氧化电位和缩短FeS2氧化峰与还原峰之间的电位差,从而催化MnO2浸出Mn2+的过程。     

Triacylglycerols of winter butterfat containing configurational isomers of monoenoic fatty acyl residues. I. Disaturated monoenoic triacylglycerols

The triacylglycerols of winter butterfat were fractionated according to the type and degree of unsaturation into six fractions by silver ion high-performance liquid chromatography (Ag-HPLC). The acyl carbon number distribution of the triacylglycerols in each fraction was elucidated by reversed-phase HPLC and mass spectrometry (MS). The MS analysis of each fraction gave deprotonated triacylglycerol [M - H]⁻ ions which were produced by chemical ionization with ammonia. The daughter spectrum of each of the [M - H]⁻ ions provided information on its fatty acid constituents. Successful fractionation of triacylglycerols differing in the configuration of one fatty acyl residue by Ag-HPLC was important because geometrical isomers could not be distinguished by the MS system used. In addition to the fatty acid compositions, reversed-phase HPLC analysis demonstrated the purity of the collected fractions: molecules having acis-trans difference were separated nearly to the baseline. Triacylglycerols differing in the configuration of one fatty acyl residue were not equally distributed in relation to their acyl carbon numbers. This indicates that during the biosynthesis of triacylglycerols,cis- andtrans-fatty acids are processed differently. Although the fatty acid compositions of the corresponding molecular weight species of disaturatedtrans- and disaturatedcis-monoenoic triacylglycerols were similar, there may be differences in the amounts of different fatty acid combinations or in the distribution of fatty acids between the primary and secondary glycerol positions. In addition to the main components, it was possible to analyze minor triacylglycerols, such as molecules containing one odd-chain fatty acid, by the MS system used.     

Plant response to pesticides and environment: Sicklepod (Cassia tora L.) fatty acid separation by gas chromatography

Fatty acid content of sicklepod (Cassia tora L.) leaves and stems was determined by GLC. Major constituents were identified as palmitate, stearate, oleate, linoleate and linolenate at 20.8%, 6.4%, 5.7%, 13.1% and 26.0%, respectively, of the total fatty acids present. The remainder of the fatty acids occurred in shorter or longer homologues and branched chain compounds. Chain lengths up to C₃₄ were found. Published as Journal Series No. 289 of the University of Georgia, College of Agricultural Experiment Stations, Ga. 30212.     

Hydrogenolysis products of the minor fatty acids fromEuphoria longana seed oil

The behavior of shorter-chain cyclopropane fatty acid components ofEuphoria longana seed oil and some other minor components during hydrogenolysis has been studied by open-tubular gas liquid chromatography on butanediolsuccinate polyester and Apiezon L substrates. The retention data and degree of resolution of the pairs of monomethylbranched fatty acids resulting from the hydrogenolysis of cyclopropane rings are used to indicate the positions of the latter in a series of fatty acids as ω9 relative to the terminal methyl group. An instance of possible isomerization of a cyclopropene fatty acid has been detected. The probable positions of monoethylenic unsaturation in fatty acids are discussed.     

Identification of diacylglycerols and triacylglycerols in a structured lipid sample by atmospheric pressure chemical ionization liquid chromatography/mass spectrometry

Atmospheric pressure chemical ionization liquid chromatography/mass spectrometry was used in the identification of diacylglycerol and triacylglycerol (TAG) molecular species in a sample of a structured lipid. In the study of acylglycerol standards, the most distinctive differences between the diacylglycerol and TAG molecules were found to be the molecular ion and the relative intensity of monoacylglycerol fragment ions. All saturated TAG ranging from tricaproin to tristearin, and unsaturated TAG including triolein, trilinolein, and trilinolenin, had ammonium adduct molecular ions [M+NH₄]⁺. Protonated molecular ions were also produced for TAG containing unsaturated fatty acids and the intensity increased with increasing unsaturation. Diacylglycerol fragment ions were also formed for TAG. The ammonium adduct molecular ion was the base peak for TAG containing polyunsaturated fatty acids, whereas the diacylglycerol fragment ion was the base peak for TAG containing saturated and monounsaturated medium- and long-chain fatty acids; the relative intensities of the ammonium adduct molecular ions were between 14 and 58%. The most abundant ion for diacylglycerols, however, was the molecular ion [M−17]⁺, and the relative intensity of the monoacylglycerol fragment ion was also higher than that for TAG. These distinctive differences between the diacylglycerol and TAG spectra were utilized for rapid identification of the acylglycerols in the sample of a structured lipid.     

Stability of lipids and polyunsaturated fatty acids during smoking of atlantic mackerel (Scomber scombrus L.)

Fall Atlantic mackerel (Scomber scombrus L.), non-smoked and hot smoked according to the method of Torry (Aberdeen, Scotland) Advisory Note #82, in an AFOS-Torry Mini Kiln, were used to study changes in oxidative rancidity and composition of major lipid classes and fatty acids. After smoking there was an increase in thiobarbituric acid (TBAM) value and peroxide (PO) value, but the values were still indicative of acceptable quality. The percentages of triglycerides (TG) and phospholipid (PL) did not change significantly, and free fatty acids could barely be detected. The overall fatty acid composition remained virtually unchanged after the smoking process. This included the longer chain C₂₀ and C₂₂ n-3 fatty acids, now regarded as potentially essential fatty acids for humans.     

Fatty Acid Composition of Sheep Tail-Fats from Five Iranian Native Breeds

Fifteen fat samples provided from 5 sheep of 5 different Iranian native breeds were examined for their fatty acid composition by means of gaschromatography. Over 30 components could be detected in most samples. Fifteen fatty acids occurred in measurable amounts commonly higher than 0.1% up to 53.5% of the total. The saturated part consisted for the major of myristic (2.4–5.5%), pentadecanoic, (0.6–1.0%), palmitic (18.2–23.6%), heptadecanoic (0.9–2.3%), stearic (7.1–22.1%) and arachidic (0.1–0.3%) acids. Myristoleic (0.3–2.1%), palmitoleic (1.4–3.6%), oleic (39.6–53.5%), linoleic (2.1–3.7%) and linolenic (2.2–2.9%) acids were the main unsaturated fatty acids identified in this investigation. The differences in fatty acid composition of fats from sheep of various breeds were considerably high in stearic and oleic acids in some cases. The variation in fatty acid composition of fat samples obtained from different parts of a tail was insignificant in all 5 sheep examined. No conclusion could be made as to whether the above mentioned considerable differences in fatty acid composition of tail fats from various sheep are due to difference in their breed or due to other factors.     

Analysis of Intact Cholesteryl Esters of Furan Fatty Acids in Cod Liver

Furan fatty acids (F‐acids) are a class of natural antioxidants with a furan moiety in the acyl chain. These minor fatty acids have been reported to occur with high proportions in the cholesteryl ester fraction of fish livers. Here we present a method for the direct analysis of intact cholesteryl esters with F‐acids and other fatty acids in cod liver lipids. For this purpose, the cholesteryl ester fraction was isolated by solid phase extraction (SPE) and subsequently analyzed by gas chromatography with mass spectrometry (GC/MS) using a cool‐on‐column inlet. Pentadecanoic acid esterified with cholesterol was used as an internal standard. GC/MS spectra of F‐acid cholesteryl esters featured the molecular ion along with characteristic fragment ions for both the cholesterol and the F‐acid moiety. All investigated cod liver samples (n = 8) showed cholesteryl esters of F‐acids and, to a lower degree, of conventional fatty acids. By means of GC/MS‐SIM up to ten F‐acid cholesteryl esters could be determined in the samples. The concentrations of cholesteryl esters with conventional fatty acids amounted to 78–140 mg/100 g lipids (mean 97 mg/100 g lipids), while F‐acid cholesteryl esters were present at 47–270 mg/100 g lipids (mean 130 mg/100 g lipids).     

Analysis of north atlantic and baltic fish oil triacylglycerols by high-performance liquid chromatography with a silver ion column

Triacylglycerols from Atlantic herring (Clupea harengus), sandeel (Ammodytes sp.) and Baltic herring (Clupea harengus membras) have been fractionated by silver ion high-performance liquid chromatography. An ion exchange column loaded with silver ions was the stationary phase, and a gradient in the mobile phase from 1,2-dichloroethane/dichloromethane (1∶1, v/v) to acetone and then to acetone/acetonitrile (2∶1, v/v) was used to effect the separation with light-scattering (i.e., mass) detection. Fractions were collected via a streamsplitter, and fatty acid methyl esters were prepared by transesterification in the presence of an internal standard for identification and quantification by gas liquid chromatography. Triacylglycerols were separated according to the number of double bonds in the fatty acyl residues. Resolution was excellent at first, when the least unsaturated molecules eluted (trisaturated to dimonoene-monodiene fractions). Base-line resolution could no longer be achieved when molecules containing trienoic or more highly-unsaturated fatty acids began to elute because of overlapping components. Nonetheless, some valuable separations of species containing two saturated and/or monoenoic fatty acids and one polyenoic fatty acid were achieved. Double bond indices (average number of double bonds in each triacylglycerol molecule) were calculated to estimate the separations possible. Fractions containing at least 11–14 double bonds per molecule were obtained.     

小决明挥发油的提取及其化学成分的GC-MS分析

分别采用超临界CO2萃取法和水蒸气法提取决明子中的挥发性成分,并用气相色谱、气质联用（GC—MS）测定和分析其化学组分。结果显示：超临界CO2萃取法得到的挥发油的主要成分分别是（Z,Z）-9,12-十八碳二烯酸（26．74％）、油酸（24．15％）、n-十六烷酸（13．99％）、大黄根酚（7．26％）、（E）-9-十八碳烯酸（4．52％）和硬脂酸（4．44％）,挥发油中主要含有脂肪酸（75．88％）和蒽醌（7．26％）,得率高于水蒸气法,其决明挥发油在保持较高的亚油酸和油酸含量同时含有更多其它成分,超临界CO2萃取法比水蒸气法更适于提取决明挥发油。     

Fatty acids of the tuna of different fishing areas of the Mexican Pacific,canned in oil and water

A direct relationship exists between the state of health and the diet, and inside this some components, such as the fatty acids (FA), influence mostly in the prevention of certain illnesses (coronary heart disease, hypertension, rheumatoid arthritis, inflammatory answer, and arterial pressure). One of the main sources of essential FA are the marine products; the tuna is a marine food of wide consumption in Mexico due its readiness and low cost. The objective of this work was to determine the profile of fatty acids (FA) in tuna canned in oil and in water coming from three fishing areas of the Mexican Pacific. There were randomly obtained 7 oil-tuna commercial marks (AA) and 5 water- tuna (AW) coming from the next fishery areas: Baja California Sur (L1), Colima (L2) and Mazatlán (L3). The samples without draining were liquefied and thereafter it was obtained the methyl esters of fatty acids that were analyzed by gas chromatography with a flame ionization detector. In all the areas were identified 20 FA (mg/100 g); three AG omega 3 (EPA, DHA and linolenic) and two omega 6 (linoleic and arachidonic). In the AA of the three areas the most abundant saturated FA were estearric and palmitic acids, the most abundant monounsaturated fatty acid was the cis-vaccenic, followed by the oleic acid. The behavior of those omega 3 in the AA of the three areas were similar: with the less quantity was the linolenic acid (447-755), continued by the EPA (979-1323) and finally high concentrations of DHA (1862-3327). In the AW the DHA was the most abundant fatty acid in all the areas (1086-4456), the most abundant monounsaturated fatty acid was the palmitic (640-3809). It was observed the presence of trans fatty acids in high quantities in AW: linolelaidic (1394-1495) and elaidic (377-1234). The relationship omega 3/omega 6 in the AA was similar in L1 and L2, and lower in L3; in AW was higher in L2 and L3. In conclusion, evident variation exists in the content of FA among areas; it could be considered that the AA of L3 and AW of L2 as the richest in omega-3 and omega-6 FA. In general, the tuna in water is a richer food in FA omega 3 and omega 6 that the tuna in oil, independently of the fishery area.