涡旋辅助液液微萃取结合GC-MS法检测67 种白酒中四甲基吡嗪、4-甲基愈创木酚4-乙基愈创木酚

采用涡旋辅助液液微萃取结合气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）法对67?种白酒中四甲基吡嗪、4-甲基愈创木酚和4-乙基愈创木酚进行检测。酒样经二氯甲烷提取,涡旋辅助萃取1?min,6?000?r/min离心5?min,然后采用GC-MS进行分析。结果表明,四甲基吡嗪、4-甲基愈创木酚和4-乙基愈创木酚分别在质量浓度为0.5～2?500、1.0～2?500、1.0～2?500?μg/L的范围内具有较好的线性关系（R2＞0.99）;检出限分别为0.25、0.5、0.5?μg/L;不同添加水平的平均回收率为80.1%～88.0%。对67?种白酒含量分析表明,所有样本都含有四甲基吡嗪,含量范围为1.5～2?434.3?μg/L;51?种样本中含有4-甲基愈创木酚,含量范围为2.8～1?709.0?μg/L;53?种样本中含有4-乙基愈创木酚,含量范围为1.3～1?167.5?μg/L。白酒酿造原料、工艺的差异可能是造成其健康因子含量不同的潜在因素。     

Fenton试剂氧化降解愈创木酚的研究

以木素类模型物愈创木酚为目标化合物,在自制的圆柱形双层玻璃反应器中,考察Fenton试剂对愈创木酚的处理效果,研究了H2O2用量、Fe^2＋用量、愈创木酚溶液初始浓度及pH值、反应时间、紫外光照射等因素对愈创木酚降解的影响。实验结果表明,在室温条件下,当体系pH值为3.0时,加入2倍理论用量的H2O2,Fe^2＋与H2O2的物质的量之比为1∶50,反应60 min后,初始质量浓度50 mg/L的愈创木酚溶液的愈创木酚去除率可达85.1%;当体系中引入紫外光照射后,Fenton试剂的氧化性明显增强,反应速度显著加快,反应进行30 min后愈创木酚可完全去除。     

愈创木酚在[C4mim]Cl-H2O中的溶解行为

采用紫外光谱和荧光光谱研究了木质素模型化合物愈创木酚(guaiacol)在[C₄mim]Cl-H₂O体系中的溶解行为。分析了[C₄mim]Cl-H₂O二元体系和[C₄mim]Cl-H₂O-guaiacol三元体系的谱图, 发现在不同[C₄mim]Cl浓度下, 紫外光谱中芳香环的K带与B带的变化不同, 对愈创木酚的溶解影响也不相同;愈创木酚的加入会使[C₄mim]Cl-H₂O出现荧光猝灭现象, 其原因在于愈创木酚与[C₄mim]Cl-H₂O形成氢键, 此弱分子间作用力影响了溶液的光谱行为。     

2-羟基-3-甲氧基苯甲醇的合成

研究了以愈创木酚为起始原料、经硼酸酯化后再与多聚甲醛进行羟甲基化合成2-羟基-3-甲氧基苯甲醇的方法,探讨了原料配比、反应温度、反应时间等反应条件对反应的影响。研究表明,该合成方法具有原料价廉易得、合成操作简便、产品纯度高等优点,具有一定的工业化前景。产物结构经核磁共振确认,HPLC测定产品纯度达到99.2%。     

Investigation on molar heat capacity,standard molar enthalpy of combustion for guaiacol and acetyl guaiacol ester

The molar heat capacities(C_p) of guaiacol(CAS 90-50-1) and acetyl guaiacol ester(AGE, CAS 613-70-7) were determinated from 290 K to 350 K by differential scanning calorimetry(DSC), and expressed as a function of temperature. Two kinds of group contribution models were used to estimate the molar heat capacities of both guaiacol and AGE, the average relative deviation is less than 10%. The standard molar enthalpies of combustion of guaiacol and AGE were- 3590.0 k J·mol~(-1)and- 4522.1 k J·mol~(-1) by a precise thermal isolation Oxygen Bomb Calorimeter. The standard molar enthalpies of formation of guaiacol and AGE in a liquid state at298.15 K were calculated to be- 307.95 k J·mol~(-1) and- 448.72 k J·mol~(-1), respectively, based on the standard molar enthalpies of combustion. The thermodynamic properties are useful for exploiting the new synthesis method, engineering design and industry production of AGE using guaiacol as a raw material.     

乙基香兰素的合成及应用

综述了乙基香兰素的几种合成方法,并对其应用进行了简单介绍。     

The effects of size, temperature and air contact on the outcome of heating oak fragments

The concentrations of the important oak aroma volatiles guaiacol, 4-methylguaiacol cis - and trans -oak lactone and vanillin in extracts of French and American oak heated under various conditions were measured using stable isotope dilution analyses coupled with gas chromatography-mass spectrometry. Heating resulted in marked increases in the concentrations of guaiacol, 4-methylguaiacol and vanillin, with more formed at higher temperature. Approximately twice as much guaiacol and 4-methylguaiacol and two to five times as much vanillin were formed by heating in the presence of air compared to heating under argon. Oak lactone concentration was less affected by heating. The effects of heating different sized oak pieces were investigated for French and American oak samples. Compared to heating larger oak pieces, heating smaller fragments of oak generated up to twice as much guaiacol and 4-methylguaiacol and two to four times as much vanillin at 235^oC for both French and American oak. This effect is ascribed to the exposure of a greater surface area of oak to air when smaller fragments are heated. Variable effects were observed for cis - and trans -oak lactone. Variation in chip size, as well as heating time and temperature, is clearly one way of obtaining different aroma profiles from oak products.     

Fecal volatiles as part of the aggregation pheromone complex of the desert locust,Schistocerca gregaria (Forskal) (Orthoptera: Acrididae)

Olfactometric bioassays showed that nymphs of crowded desert locusts,Schistocerca gregaria, aggregated in response to volatiles derived from their feces and to volatiles emitted from the feces of young adults, but were indifferent to volatiles emitted by older adult feces. On the other hand, young and older adults were not only responsive to their own fecal volatiles but also cross-responsive to each other's and that of the nymphs. Charcoal-trapped volatiles from the feces and synthetic blends of the fecal volatiles also elicited similar responses. Young adults responded moderately to a blend of nymphal volatiles and those derived from nymphal feces. GC-EAD and GC-MS analysis of the trapped volatiles revealed the presence of guaiacol and phenol as predominant electrophysiologically active components of nymphal and young adult feces. Fecal volatiles of older adult contained phenylacetonitrile in addition to guaiacol and phenol, which were present in relatively lower proportion. These results suggest that fecal volatiles are part of the aggregation pheromone complex of the desert locust, which includes the pheromone blends produced by nymphs and older adults, respectively.     

愈疮木酚和乙醛酸合成香兰素研究

对愈疮木酚和乙醛酸缩合—氧化合成香兰素路线进行了中等规模的研究。当反应温度为5 0℃ ,pH值为 12 ,愈疮木酚和乙醛酸物质的量比为 1 5∶1 0 ,缩合反应中乙醛酸的转化率可至90 %。以氢氧化铜为催化剂 ,以氧气为氧化剂 ,在pH值为 12 5和 94℃下反应 ,氧化产率为94%。香兰素的总收率 (以乙醛酸为基准 )为 70 %～ 72 %。生产废水经简单处理后可重复使用 ,并不影响收率 ,废水量可控制在 5t/t香兰素的水平。