阳信洼陷烃源岩评价

在分析了阳信洼陷烃源岩多种有机地球化学参数的基础上,对其有机质丰度、类型及成熟度进行了研究。结果表明,阳信洼陷沙一段至沙四段上亚段为好一优质烃源岩,沙四段下亚段为差烃源岩。烃源岩有机质热演化划分为3个阶段：未成熟生物气阶段、低熟油生成阶段和成熟油生成阶段。阳信洼陷主力烃源岩在沙三段和沙四段上亚段,这两个层段是今后勘探的重点层段。     

Phenolic resins for can coatings: I. Phenol-based resole analysed by GC-MS, GC×GC, NPLC-GC and SEC

Phenolic resins (resoles) are used for curing expoxy and polyester coatings, e.g., for food cans. They consist of oligomeric materials prepared from phenols (phenol, cresol, tert.-butyl phenol), formaldehyde and butanol and are an analytical challenge because of the complexity of their composition. A phenol-based resole was selected for a first investigation of various analytical techniques: gas chromatography (GC)-mass spectrometry (MS), comprehensive two-dimensional GC (GC×GC), normal phase high-performance liquid chromatography (NPLC, primarily of interest for preseparation for GC analysis), and size exclusion chromatography (SEC). Mass spectra are discussed for some selected compounds and a list of spectra is added. GC×GC was the most powerful method for separating and visualizing the composition of the complex mixture, but the whole battery of methods might be needed to characterize resoles and to analyse their migration into food or food simulants.     

Antioxidant activity and polyphenol content of Turkish thyme (Thymus vulgaris) monitored by liquid chromatography and tandem mass spectrometry

Like tea, the leaves of Turkish thyme (Thymus vulgaris) can be boiled in water to produce an extract. This is widely used as syrup for the treatment of coughs and bronchitis at alternative medicine clinics in many parts of the world. In the current study, we assessed the phenolic content and antioxidant activity of thyme. The antioxidant activities of both ethanol and aqueous extracts of thyme were determined using various in vitro methods. The total phenolic and total flavonoid contents were determined to be a gallic acid equivalent and a quercetin equivalent, respectively. Finally, the quantities of the phenolic compounds were detected using high-performance liquid chromatography and tandem mass spectrometry. The total phenolic compounds in the aqueous extract and ethanol extracts of Turkish thyme were 256.0 μg gallic acid equivalent/mg dried extract and 158.0 μg gallic acid equivalent/mg dried extract, respectively. Conversely, the total flavonoid compounds in both extracts were 44.2 μg and 36.6 μg quercetin equivalent/mg dried extract, respectively. For the first time, we determined phenolic contents and investigated the antioxidant potential of thyme. The results indicate that Turkish thyme is a good dietary source with phenolic properties.     

ICP-OES在分析有机样品中金属元素常见故障排除及注意事项

使用合适的有机溶剂将有机样品稀释后直接导入电感耦合等离子体发射光谱仪（ICP-OES）测定有机物中金属元素的方法,前处理简单,测定速度快,但由于ICP-OES直接分析有机物时常出现点炬困难、容易熄炬、炬管断裂等问题,此方法未得到广泛应用。本文以美国Perkin Elmer公司Optima 7000DV型ICP-OES为例,对ICP-OES在分析易挥发有机样品过程中出现的常见故障及排除方法进行探讨,并介绍了分析有机物的注意事项。     

Effect of preliminary processing and method of preservation on the content of selected antioxidative compounds in kale (Brassica oleracea L. var. acephala) leaves

Vitamin C and polyphenol content as well as total antioxidative activity were investigated in fresh leaves of kale; in leaves after blanching or cooking; and in frozen and canned leaves. In 100 g fresh matter, kale leaves contained 384.9 mg polyphenols and 112.1 mg vitamin C, with a Trolox equivalent antioxidant capacity (TEAC) level of 1175 μM Trolox. Of the polyphenols identified in kale leaves, ferulic acid occurred in the highest amount (240.44 mg/100 g, constituting 62% of total polyphenols). Freezing was a better method of preserving kale leaves since the loss of nutritive constituents was lower than in the case of canning. Depending on preliminary processing and storage temperature, after one-year storage frozen leaves contained 82.9–171.3 mg polyphenols and 39.3–65.4 mg vitamin C, with TEAC at the level of 501–681 μM Trolox in 100 g. In canned leaves these values were: 91.3–94.1 mg polyphenols, 16.1–19.3 mg vitamin C and 268–293 μM Trolox.     

Phenolic acids in caryopses of two cultivars of wheat, rye and triticale that display different resistance to pre-harvest sprouting

 This study confirmed the significant role of phenolics in the dormancy of cereal caryopses. Investigations were conducted on two cultivars of wheat (Elena and Alba), rye (Amilo and Dańkowskie Złote), and triticale (Ugo and Bogo), with characteristic deeper or shallow dormancy, respectively. In germination studies, cultivars susceptible to sprouting (Alba, Dańkowskie Złote and Bogo) displayed higher germination percentages than those resistant to sprouting (Elena, Amilo and Ugo). The phenolic acid contents (i.e. free, liberated from soluble esters, and liberated from soluble glycosides) in caryopses were determined by an HPLC method. Caffeic, p-coumaric, ferulic and sinapic acids were the dominant phenolic acids detected. The majority of phenolic acids were found in the form of soluble esters. For all species examined, the levels of phenolic acids liberated from soluble esters and the total phenolic acid contents in caryopses showing shallow dormancy were higher than in those showing deeper dormancy. Slight differences in the UV spectra of extracts of phenolic compounds from caryopses showing shallow or deeper dormancy were noted. Received: 6 April 1999     

Preparing phenolic resins using pulping spent liquor

The method of using spent liquor (SL) obtained from the chemical pretreatment stage of wheat straw semi-chemical pulping to prepare spent liquor phenolic resins (SLPR) was investigated in the present work. In this work spent liquor was modified with phenol, and then the modified spent liquor was further synthesized with phenol and formaldehyde under appropriate conditions. Experimental data shows that the substitution mass fraction of spent liquor for phenol, the mole ratios of formaldehyde and sodium hydroxide to phenol, temperature and duration time of addition and condensation reaction all show significant influence on the properties of SLPR. SLPR and pure phenolic resins (PR) exhibited almost the same macromolecular structures characterized by FT-IR, and the main properties of the SLPR such as free formaldehyde content, gel time and bonding strength demonstrated superiority to that of PR.     

端羟基PU半预聚体改性酚醛发泡材料的研究

采用端羟基聚氨酯(PU)半预聚体改性酚醛发泡材料,研究了端羟基PU半预聚体的结构、用量等因素对增韧效果的影响。结果表明,采用端羟基PU半预聚体法能够有效增加发泡材料的回弹性,在设计n(OH)/n(NCO)为4/1、端羟基PU半预聚体用量占总量2%～8%(质量分数)下,增韧效果良好。     

Accumulation of metals and selected nutritional parameters in the field-grown chamomile anthodia

Accumulation of metals and selected nutritional parameters of chamomile (Matricaria chamomilla) anthodia cultured under natural condition on an experimental field in Košice (Slovak Republic) were studied. Two official cultivars (diploid ‘Novbona’ and tetraploid ‘Lutea’) and two ontogenetic phases of anthodia (‘bud’ and ‘flower’) were compared. K, Ca, Mg, Al, Cu, Cr, Hg and Cd were more accumulated in both bud and flower of diploid plants while accumulation of Fe, Zn, Ni and Pb was ploidy-independent. Bioaccumulation factor was lower than one for toxic metals, indicating that chamomile is an excluder. Tetraploid plants contained lower concentrations of amino acids but higher concentrations of phenolic acids compared to diploid plants. Among phenolic acids, caffeic and vanillic acids were mainly present in the glycosidic form. Reducing sugars (glucose equivalents), total soluble phenols, sum of flavonols, individual flavonols (quercetin and kaempferol), apigenin and herniarin were more accumulated in anthodia of tetraploid plants. Our data indicate that increase in ploidy level reduces accumulation of toxic metals and amino acids but enhances accumulation of phenolic metabolites. Thus polyploidisation is a good tool to achieve safer chamomile cultivars for pharmaceutical purposes.     

LC/ESI-MS/MS characterisation of procyanidins and propelargonidins responsible for the strong antioxidant activity of the edible halophyte Mesembryanthemum edule L.

Mesembryanthemum edule is used as a food ingredient and in traditional medicine. In this study, we investigated antioxidant activities of several extracts (methanol/acidified water, v/v: 20/80; 40/60 and 60/40) obtained from M. edule leaf, stem and root. Then, individual phenolics were characterised by reverse-phase HPLC coupled to electrospray ionisation mass spectrometry and multi-stage MS fragment analysis. Results showed that 40% methanol leaf extract, 40% methanol root extract and 20% methanol stem extract displayed the highest scavenging activity against DPPH and ABTS radicals. Regarding LC/ESI-MS/MS identification of active phenols, there were significant differences among the fractions of interest. In fact, 40% leaf extract mainly contained procyanidins, whereas propelargonidins were the major phenolics in 20% methanol stem extract, while, in 40% root extract, the active compounds remained unidentified. These results indicate that edible M. edule can be used as a nutraceutical in the pharmaceutical industry.