氢化松香蔗糖酯的合成与表征

以碱性皂为乳化剂和催化剂,在(125±1)℃、反应物料物质的量之比1:1,真空度0.090Mpa及无溶剂的条件下,通过氢化松香乙酯与蔗糖的酯交换反应合成了氢化松香蔗糖酯(HRSE).用TLC、IR、UV、HPLC、HPLC-MS、13CNMR等多种方法对产物进行了分析和表征,并测得产物的临界胶束浓度(CMC)为0.009mol/L,此时的表面张力为47mN/m.     

Sequential extractions and 31P-NMR spectroscopy of phosphorus forms in animal manures, whole soils and particle-size separates from a densely populated livestock area in northwest Germany

The solubility and forms of phosphorus (P) were investigated in manures from chicken and pigs, eight whole soil samples and clay-, silt-, and sand-size separates from an arable and a grassland soil. Total P (P_t) in liquid pig manure (16.2 g kg^–1) and dry chicken manure (26.2 g kg^–1) was distributed between residual P (39–41% P_t), H₂SO₄–P (17–27% P_t), labile resin- and NaHCO₃–P (24–39% P_t), and NaOH-P (3–10% P_t). Most soils had larger proportions of NaOH-P and residual P, indicating reactions of manure-derived P compounds with pedogenic oxides and humic substances. Clay-size separates had the highest P-concentrations in all fractions and were particularly enriched in exchangeable and labile P forms. Solution ³¹P-nuclear magnetic resonance (NMR) spectra of 0.5 M NaOH extracts from manures and some soil samples showed greater signal intensities for orthophosphate and monoester P than 0.1 M NaOH extracts. This can be explained by alkaline hydrolysis phosphate diesters at higher NaOH concentrations and/or by preferential extraction of diesters at lower concentrations. The ³¹P-NMR spectra showed differences between the two manures and confirmed that increasing proportions of ester-P can be expected if they are spread to soils. The NaOH extracts of soil samples were characterized by large proportions of orthophosphate-P (mean 77% of assigned P compounds), which seemed to be slightly enriched in clay fractions whereas the extracts from silt contained more ester-P. Sequential extractions and ³¹P-NMR spectroscopy both showed that these excessively manured soils are likely to lose large amounts of P. Received: 15 July 1996     

强碱催化大豆油酯交换制备生物柴油

研究大豆油在NaOH催化作用下与甲醇经过酯交换反应制备生物柴油的过程,考察了催化剂用量、醇油摩尔比、反应温度、搅拌速度和不同级别甲醇对反应的影响,采用气相色谱(氢火焰)内标法分析产品中脂肪酸甲酯的含量.结果表明,该反应的最适宜工艺条件为:催化剂用量1.0%(相对于油脂质量)、醇油摩尔比6:1、反应温度65℃、搅拌速度400 r/min.大豆油在最优工艺条件下,经过酯交换反应得到的甲酯含量达到了98%～99%.     

苏南地区农田表层土壤中多环芳烃和酞酸酯的污染特征及来源

采用气相色谱质谱（GC-MS）法测定了苏南地区13个农田表层土壤样品中的多环芳烃（PAHs）和酞酸酯（PAEs）污染物,分析比较了不同区域农田表层土壤,尤其是来自钢铁企业周边的表层土壤中PAHs和PAEs的污染特征及其来源。结果表明,苏南地区农田土壤中总PAHs和总PAEs的浓度分别在147～40300μg·kg-1和0.575～762μg·kg-1之间,其中钢铁厂周边的平均浓度分别为6130μg·kg-1和47.4μg·kg-1。土壤样品中苯并（a）芘的浓度与总PAHs的浓度显著相关,高分子量PAHs在钢铁厂周边表土中含量较高,钢铁冶炼焦化和烧结等工序是其污染来源。酞酸正丁酯（DBP）和酞酸乙基己基酯是苏南地区农田土壤中含量最高的两种PAEs类物质,钢铁厂周边有较高的DBP检出可能与炼钢、冷轧和炼铁等工序有关。本研究将为经济高速发展地区农田土壤环境质量评价、农产品安全生产及土壤污染防治对策的制定提供科学依据。     

土壤样品中酞酸酯含量分析的前处理研究——提取液浓缩过程与净化的影响

通过比较索氏提取和超声提取这两种提取土壤酞酸酯的方法,认为从提高回收率和降低背景干扰角度出发,超声提取法更合适作为土壤酞酸酯分析的前处理。针对超声提取过程中的一些操作步骤的细节做了比较研究,表明提取液不蒸干可减少酞酸酯的挥发损失,提取液过净化柱与否对GC-MS分析多数酞酸酯组分影响不大,不过净化柱处理可提高土壤酞酸酯的分析效率,但土壤中过多的色素干扰可能会影响某些组分(如邻苯二甲酸二(2-乙基)己酯)的分析结果。     

Effect of esterification on the absorption of astaxanthin in rainbow trout, Oncorhynchus mykiss (Walbaum)

Gastrointestinal and serum absorption of astaxanthin was studied in rainbow trout, Oncorhynchus mykiss (Walbaum) (217 ± 2 g) fed diets supplemented with either esterified astaxanthin (from Haematococcus pluvialis) or free astaxanthin (synthetic, as 8% w/w beadlets) at similar levels (50 mg kg^?1). After 56 days of feeding, there was a significant difference (P = 0.0582) between steady‐state serum astaxanthin concentrations for fish fed free (2.0 ± 0.3 μg mL^?1) or esterified astaxanthin (1.3 ± 0.1 μg mL^?1) at the 90% confidence level. However, following ingestion of a single meal supplemented with free or esterified astaxanthin, the rates of astaxanthin absorption into serum were not significantly different (P > 0.1) (0.8 ± 0.2 µg mL^?1 h^?1 and 1.0 ± 0.4 µg mL^?1 h^?1 respectively). In fish fed both free or esterified astaxanthin, higher absorption (P < 0.05) of astaxanthin by the ileal (0.8 ± 0.14 μg g^?1 and 0.9 ± 0.15 μg g^?1 respectively) compared with the posterior (0.2 ± 0.01 μg g^?1 and 0.3 ± 0.14 μg g^?1 respectively) intestine was recorded. This confirmed the role of the anterior intestine in carotenoid absorption. Non‐detectable levels of esters in digesta taken from the hind intestine suggest the anterior intestine is also the primary region for ester hydrolysis.     

典型塑料生产加工地块土壤邻苯二甲酸酯及多环芳烃污染特征和健康风险

为探究塑料生产加工造成的土壤污染,采用气相色谱-质谱联用法分析了南方典型塑料生产加工地块土壤中邻苯二甲酸酯(PAEs)和多环芳烃(PAHs)的含量水平,并开展健康风险评价。结果表明:PAEs化合物中仅邻苯二甲酸二(2-乙基己基)酯(DEHP)被检出,检出率为80.6%,平均值为16.0 mg·kg^-1,最高值为1300 mg·kg^-1,该值是迄今为止我国土壤中检出PAEs化合物的最高值。15种优控PAHs化合物均有不同程度地检出,总检出率为33.1%,检出总量为0~35.4 mg·kg^-1,平均值1.7 mg·kg^-1。以《土壤环境质量建设用地土壤污染风险管控标准(试行)》(GB 36600—2018)第一类用地筛选值进行评价,DEHP、苯并(a)芘(BaP)和二苯并(a,h)蒽(DahA)超标,超标率分别为1.4%、5.0%和1.4%。DEHP在管材车间超标,与聚氯乙烯管材(PVC)生产和存储有关;BaP和DahA在原料仓库超标,且BaP还在油墨仓库及印刷复合车间超标,与煤和重油作为燃料使用以及油墨释放PAHs化合物有关。3种超标化合物含量和检出率均随土层深度的增加明显降低。健康风险评价显示,DEHP、BaP和DahA的非致癌风险均在可接受范围,但部分样品的DEHP(1.4%)和BaP(2.8%)的致癌风险超过可接受风险水平,主要由经口摄入和皮肤接触造成。研究表明塑料生产加工可导致较为严重的土壤PAEs和PAHs污染。     

Analysis of free phytosterols/stanols and their intact fatty acid and phenolic acid esters in various corn cultivars

The contents and the compositions of free sterols/stanols, steryl/stanyl fatty acid esters and steryl/stanyl phenolic acid esters were determined in 25 corn cultivars grown at the same location and in the same year. The lipid extracts obtained from the flours of whole kernels were subjected to solid-phase extraction for the isolation and separation of the sterol classes, followed by capillary gas chromatography. The study provides for the first time information on the variability of individual steryl/stanyl fatty acid esters in corn cultivars. The analysis revealed pronounced differences in total contents of each sterol class. The levels of free sterols/stanols ranged from 298 to 433 μg/g dry matter flour, those of steryl/stanyl fatty acid esters from 430 to 1187 μg/g and those of steryl/stanyl phenolic acid esters from 46 to 240 μg/g. Free sterols/stanols were mainly composed of sitosterol and campesterol; up to 11% were made up of stanols. Steryl/stanyl esters of C18-fatty acids were dominating, with sitosteryl linoleate as the most abundant ester (44.7–53.5% of total fatty acid esters). Among the three investigated sterol classes, the distribution patterns of steryl/stanyl phenolic acid esters showed the greatest variability between the cultivars, even though trans-sitostanyl ferulate was the dominating ester in all samples.     

Spectroscopic and chromatographic evaluation of the wax ester fraction of Adenanthera pavonina oil

Present study was carried out in order to assess the constituents of Adenanthera pavonina wax esters by Fourier Transform Infrared (FT-IR) spectroscopy and Gas chromatography (GC). After extraction of oil from A. pavonina seeds, wax esters were separated from oil by centrifugation and then purified through crystallization process in acetone. The white crystalline solid with melting point of 83-85 °C was initially characterized as wax esters by FT-IR. Gas chromatography with flame ionization detector (GC-FID) provided the separation of various wax esters from C₃₄ to C₄₈ including odd and even chain esters. C₄₆ wax ester was found to be predominant. For separation, identification and estimation of individual constituents of fatty acid methyl esters and fatty alcohol acetates were carried out by GC-MS after saponification and derivatization of wax esters. GC-MS analysis indicated the presence of saturated methyl esters from C_l4 to C₃₀. Predominant methyl ester was C₂₂. Wax esters contained the saturated fatty alcohols from C₁₄ to C₂₈. The major alcohol was saturated C₂₄ fatty alcohol. The results indicated that A. pavonina wax esters have potential to be used in pharmaceutical and cosmetic industry due to its better composition of long chain fatty acids and fatty alcohols.     

地膜中酞酸酯类化合物及重金属对土壤一大豆体系的污染研究

在盐化草甸土和草甸白浆土上,采用田间试验研究了大豆各生育时期不同地膜残留量土壤和植株中邻苯二甲酸二丁酯（DBP）、邻苯二甲酸二异辛酯（DEHP）及重金属Pb、Cd含量的差异性。试验结果表明,大豆各生育时期,高倍地膜残留量土壤和植株中DBP、DEHP含量高于低倍残留量,各处理间差异达到显著水平,植株中未检测出DEHP。对照（CK）处理土壤中DBP和DEHP含量随着生育周期延长显著降低,1倍和3倍地膜残留量处理则呈增加趋势;对DBP和DEHP含量与生育时期做相关分析,各处理均为显著相关。各生育时期,高倍地膜残留量土壤中Pb、Cd含量均高于低倍残留量,处理间达到显著水平。相同处理各生育时期,土壤中Pb、Cd含量无明显变化。1倍和3倍处理植株和籽粒中Pb、Cd含量差异不显著,各处理籽粒中Pb、Cd含量低于植株。盐化草甸土和草甸白浆土试验结论相同。