稀土改质催化剂对废食用油制备燃料油的影响

利用浸渍法制备稀土改质催化剂,用于废食用油脂催化裂解的裂解气催化改质。考察了催化剂活性组分含量、硅铝比、焙烧温度、改质反应温度对产物组成、烯烃含量及收率的影响。得最佳条件:ZSM-5作为催化剂载体,催化剂活性组分镧稀土含量为6%,催化剂焙烧温度为550℃,改质反应温度为360℃。在最佳条件下催化改质,燃料油烯烃含量降低了34.3%,汽油含量提高了14.36%,轻柴油含量提高了1.67%,重柴油含量下降了6.72%,重油含量下降了2.2%,燃料油总收率提高了7.12%,油品质显著提高。     

六月霜中总黄酮和元素含量的分析

用分光光度法测定了六月霜中总黄酮的含量,用原子吸收分光光度法测定了六月霜中元素的含量。结果表明,六月霜中总黄酮含量为６％,Ｍｎ含量较高。     

柠檬酸含量测量不确定度的评定

分析了测定柠檬酸含量测量不确定度的来源,评定了柠檬酸含量测定过程中测量重复性、天平、滴定管、标准溶液浓度等因素对柠檬酸含量测量不确定度的影响,计算得柠檬酸含量测定结果的扩展不确定度为0．36％。在柠檬酸含量的测定过程中,滴定管的准确度是影响柠檬酸含量测量不确定度的主要因素。     

瑞安市0～7岁健康儿童头发中微量元素分析

用火焰原子吸收法检测了瑞安市５５２例０￣７岁儿童头发中锌、铁铜、钙必需元素含量,并探讨了元素含量与年龄,性别的关系,结果显示,元素含量与性别差异无显著意义;锌,钙元素含量随着年龄增长有相似变化,新生儿发铁含量明显低于其他年龄组。提示,在不同年龄儿童之间头发中元素含量存在着一定差异。     

化橘红与其它产地橘红元素含量的比较分析

用原子吸收分光光度法测定了三个不同产地橘红的元素含量，并比较了它们之间各种元素含量的差异。结果表明，化州橘红的Ｃｕ，Ｃａ含量显著低于其它产地橘红，而其它元素含量差异不大。     

硝酸铈铵中铈的价态分析

讨论了硝酸铈铵中铈的价态分析问题.硫酸亚铁铵法测定样品中的四价铈含量;盐酸羟胺还原四价铈后,EDTA法滴定样品中总铈含量;总铈含量与四价铈含量之差为样品中三价铈含量.     

铕对小麦根可溶性钙含量的影响

研究了Ｅｕ对小麦细胞内Ｃａ＾２＋含量的影响方式,用原子吸收光谱法对根的可溶性钙,总钙含量进行了测定,结果表明,短时间内Ｅｕ＾３＋促进根细胞可溶性钙含量增加,而随着处理时间的延长,可溶性钙含量下降,但总钙含量不断增加;     

健康猕猴血液和毛发微量元素含量的正常值测定和差异比较

对猕猴(Macaca mulatta)血液和毛发的镁、锰、钼、镍、铅、铬、镉、锌、铁、铜、钙等11种元素的含量，用电感耦合高频等离子体发射光谱仪进行了测定．给出了各个元素在血液和毛发中的平均含量值和变动范围．指出毛发中的微量元素含量一般较血液为高，且变动较小．与人体内含量比较，猴毛发的Cu、Mo、CA、Ni的含量与人发接近；猴血液的Zn、Fe、Ca、Mn、Ca亦与人的接近．对猴血液微量元素含量随年龄、体重、性别变化及血液含量和毛发含量的相关关系进行了统计学检验．通过对测定值的比较分析，认为尽管动物体内的微量元素含量随种类、环境、个体差异变化较大，就群体平均含量而言，仍存在着相似的变化规律。本文的测定结果对了解猕猴对微量元素的需要提供了初步依据．     

8种花岗岩金属元素含量测定及比较研究

报道了８种花岗岩的金属元素含量，并比较了不同品种花岗岩的金属元素含量的差异，结果发现它们分别呈现非常显著性差异，显著性差异和无显著性差异。花岗岩中铅的含量很高，镉的含量也较高，故使用时应加以注意。     

酒后驾车人员体内酒精含量的检测

酒后驾车造成的交通事故频频发生,要判断是否酒后驾驶,就要对驾驶人员进行体内酒精含量检测。阐述了血液酒精含量、呼气酒精含量、唾液酒精含量检测的基本原理和有关化学反应。     

紫荆花与玫瑰茄微量元素含量的比较研究

首次报道紫荆花十种微量元素含量，并与玫瑰茄作了含量比较研究．     

木槿叶中混合氨基酸的提取工艺研究

以浓盐酸和乙醇溶液为提取剂,分别通过加热回流和超声波组织破碎法提取了木槿叶中的混合氨基酸,确定了氨基酸提取的最佳工艺条件。结果表明,用盐酸回流提取,盐酸与木槿干粉的液料比为25∶1,盐酸浓度6 mol/L,100℃下回流提取5 h,提取3次,氨基酸的提取效果最佳,提取率可达16.76%,产品收率可达8.6%。用80%乙醇溶液,室温下超声波提取30 min,提取3次,提取效果最好,提取率可达17.42%,产品收率可达8.93%。     

Potential of Hibiscus sabdariffa L. and Hibiscus Acid to Reverse Skin Aging

Hibiscus sabdariffa L. (HS) has a long history of edible and medicinal uses. In this study, the biological activities of the extracts, chromatographic fractions, and hibiscus acid obtained from HS were evaluated for their potential bioactivities. Their ability to promote extracellular matrix synthesis in skin fibroblasts was evaluated by enzyme-linked immunosorbent assays. Their anti-inflammatory activity was evaluated in a nitric oxide (NO)–Griess inflammatory experiment. Furthermore, hibiscus acid was found to have a strong anti-oxidative stress effect through the establishment of an oxidative stress model induced by hydrogen peroxide. Several assays indicated that hibiscus acid treatment can effectively reduce extracellular adenosine triphosphate (ATP) secretion and carbonyl protein production, as well as maintain a high level of reduced/oxidized glutathione (GSH/GSSG) in skin cells, thus providing a possible mechanism by which hibiscus acid can counter antioxidative stress. The present study is the first to explore the reversing skin aging potential and the contributory component of HS.     

Isolation and Properties of a Biocidal Peptide from Hibiscus cannabinus Seeds

The fungitoxicity of a biocidal peptide from kenaf Hibiscus cannabinus L. seeds was investigated. Its influence on the distribution of calcium ions in mycelial cells of the fungus Verticilluim dahliae Kleb. was examined.     

Green synthesis of palladium nanoparticles using Hibiscus sabdariffa L. flower extract: Heterogeneous and reusable nanocatalyst in Suzuki coupling reactions

An elementary and ecological method has been designed for the biosynthesis of palladium nanoparticles, through the utilization of aqueous extract of red tea (Hibiscus sabdariffa L.) as a reducing and stabilizing agent. The nanoparticles obtained were characterized through UV–visible spectroscopy, transmission election microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning election microscopy, energy‐dispersive X‐ray analysis and inductively coupled plasma analysis. The nanoparticles with spherical shape and dimensions of approximately 10 nm were used as a heterogeneous catalyst for Suzuki coupling reactions under mild conditions. The high efficiency of the catalytic reaction was affirmed by the good yields of products, easy work‐up, absence of palladium leached from the support and smooth recovery of catalyst.     

荧光法猝灭测定木槿叶中混合氨基酸的总量

在乙酸-乙酸钠缓冲介质中,氨基酸能猝灭壳聚糖-茚三酮体系荧光,基于此,对木槿叶中混合氨基酸进行测定,并对该方法的测定条件进行了讨论.线性范围为0.5～3.0 mmol/L,检出限为0.1 mmol/L.木槿叶干粉中游离氨基酸的质量分数为10.18%,相对标准偏差为1.3%,回收率为102.5%～94.3%.     

Modulation of Renal Function in a Metabolic Syndrome Rat Model by Antioxidants in Hibiscus sabdariffa L.

Metabolic syndrome (MS) is the association of three or more pathologies among which obesity, hypertension, insulin resistance, dyslipidemia, and diabetes are included. It causes oxidative stress (OS) and renal dysfunction. Hibiscus sabdariffa L. (HSL) is a source of natural antioxidants that may control the renal damage caused by the MS. The objective of this work was to evaluate the effect of a 2% HSL infusion on renal function in a MS rat model induced by the administration of 30% sucrose in drinking water. 24 male Wistar rats were divided into 3 groups: Control rats, MS rats and MS + HSL rats. MS rats had increased body weight, systolic blood pressure, triglycerides, insulin, HOMA index, and leptin (p ≤ 0.04). Renal function was impaired by an increase in perfusion pressure in the isolated and perfused kidney, albuminuria (p ≤ 0.03), and by a decrease in clearance of creatinine (p ≤ 0.04). The activity of some antioxidant enzymes including the superoxide dismutase isoforms, peroxidases, glutathione peroxidase, glutathione-S-transferase was decreased (p ≤ 0.05). Lipoperoxidation and carbonylation were increased (p ≤ 0.001). The nitrates/nitrites ratio, total antioxidant capacity, glutathione levels and vitamin C were decreased (p ≤ 0.03). The treatment with 2% HSL reversed these alterations. The results suggest that the treatment with 2% HSL infusion protects renal function through its natural antioxidants which favor an improved renal vascular response. The infusion contributes to the increase in the glomerular filtration rate, by promoting an increase in the enzymatic and non-enzymatic antioxidant systems leading to a decrease in OS and reestablishing the normal renal function.     

Variations in chemical fingerprints and major flavonoid contents from the leaves of thirty‐one accessions of Hibiscus sabdariffa L.

The leaves of Hibiscus sabdariffa L. have been used as traditional folk medicines for treating high blood pressure and fever. There are many accessions of H. sabdariffa L. throughout the world. To assess the chemical variations of 31 different accessions of H. sabdariffa L., fingerprinting analysis and quantitation of major flavonoids were performed by high‐performance liquid chromatography (HPLC). The HPLC method was validated for linearity, sensitivity, precision, repeatability and accuracy. A quadrupole‐time‐of‐flight mass spectrometry (Q‐TOF‐MS) was applied for the characterization of major compounds. A total of 9 compounds were identified, including 6 flavonoids and 3 phenolic acids. In the fingerprint analysis, similarity analysis (SA) and principal component analysis (PCA) were used to differentiate the 31 accessions of H. sabdariffa L. Based on the results of PCA and SA, the samples No. 15 and 19 appeared much different from the main group. The total content of five flavonoids varied greatly among different accessions, ranging from 3.35 to 23.30 mg/g. Rutin was found to be the dominant compound and the content of rutin could contribute to chemical variations among different accessions. This study was helpful to understand the chemical variations between different accessions of H. sabdariffa L., which could be used for quality control. © 2015 The Authors Biomedical Chromatography Published by John Wiley & Sons Ltd.     

Selective extraction, separation, and identification of anthocyanins from Hibiscus sabdariffa L. using solid phase extraction-capillary electrophoresis-mass spectrometry (time-of-flight /ion trap)

A method for selective extraction using SPE, electrophoretic separation at basic condition and the identification by using exact masses and fragmentation patterns has been developed in order to know the anthocyanins in dried calyces of Hibiscus sabdariffa L. A detailed and comparative study of several extraction procedures has been carried out to obtain the maximum number of anthocyanidins from the calyces and then a CE-TOF-MS method in positive mode using ESI has been developed for the separation and rapid identification of anthocyanins in H. sabdariffa L. Delphinidin-3-sambubioside, cyanidin-3-sambubioside have been detected as main components and cyanidin-3-O-rutinoside, delphinidin-3-O-glucoside and cyanidin-3,5-diglucoside, and chlorogenic acid as minor constituents. The confirmation of the anthocyanidins and chlorogenic acid was carried out using fragmentation ions with the IT-mass spectrometer (IT-MS).     

Tetracyclic triterpenoids isolated from semi-mangrove plant Hibiscus tiliaceus

A continuing phytochemical study on the semi-mangrove plant Hibiscus tiliaceus yielded two new tetracyclic triterpenoids （3β,24S）-19（10→9）-abeo-8α,9β,10α-eupha-5,25（26）-dien-3,24-diol （tiliacol A, 1 ）, and （3β,23Z）-19（10→9）-abeo-8α,9β,10α-tircalla-5,23-dien-3,25-diol （tiliacol B, 3）, together with one known analog （2）. Their structures were elucidated on the basis of extensive spectral analyses （MS, IR, 1D NMR and 2D NMR） and comparison with literature compounds. Compound 2 showed potent cytotoxicity against both P388 and HeLa cells with ICon values of 11.2 μmol/L and 11.5 μmol/L, resoectively.