气相色谱法测定水产品中氯霉素残留

介绍了水产品中氯霉素残留量测定的气相色谱法。样品中的氯霉素用乙酸乙酯提取,正己烷去脂肪,过Sep-C18柱进行净化,用BSTFA-TMCS衍生后进带有微电子俘获器的气相色谱仪检测。该方法的线性范围为0.5～500μg·L-1,相关系数r=0.999,最低检测限为0.1μg·kg-1,相对标准偏差为4.3%～11.0%,向样品中分别添加1μg·kg-1、10μg·kg-1和20μg·kg-13个浓度水平的氯霉素,回收率分别为62.0%、88.2%和96.4%。方法灵敏度高,准确可靠,适合水产品中氯霉素残留量的检测。     

南海8种低值小杂鱼脂肪含量和脂肪酸组成分析

采用氯仿-甲醇法提取南海盛产的8种低值小杂鱼肌肉、鱼头、内脏中的粗脂肪,利用气相色谱分析其脂肪酸的组成。结果表明,低值小杂鱼头部粗脂肪含量为2.7%～9.7%,内脏粗脂肪含量为2.9%～6.2%,肌肉部分粗脂肪含量为2.0%～8.5%;不同低值小杂鱼的脂肪酸组成基本相同,但其含量有所差异,饱和脂肪酸含量最高,都在40%以上,内脏粗脂肪中的饱和脂肪酸含量较头部和肌肉中的含量高;多不饱和脂肪酸含量差异较大,粗脂肪含量较高的鱼中多不饱和脂肪酸的含量较低;不同鱼种不同部位的粗脂肪中EPA、DHA含量有所差异。蓝圆鲹的头部粗脂肪中DHA和EPA最高,含量达到28.4%,而双带海鲱鲤内脏粗脂肪中的EPA和DHA含量仅为7.26%。     

气相色谱-嗅觉测量法鉴定蒌蒿中的香气化合物

 采用顶空固相微萃取法提取了蒌蒿样品中的挥发性成分, 利用气相色谱-嗅觉测量法(GC-O)并结合气相色谱质谱联用分析(GC - MS) , 鉴定了萎蒿中的香气化合物。共检出21个呈香化合物, 基于其嗅感强度, 反式- 2 - 己烯醛、水芹烯、顺式- 罗勒烯、3 - 崖柏酮、樟脑, 黄瓜醛、( - ) - 龙脑和( - ) - 乙酸龙脑酯被认定为形成蒌蒿香气的重要化合物。     

Antioxidant properties of blackberry and blueberry fruits grown in the Black Sea Region of Turkey

Seven wild and ten cultivated blackberries (Arapaho, Bartin, Black Satin, Bursa 1, Bursa 2, Cherokee, Chester, Jumbo, Navaho, and Ness), and six lowbush (Vaccinium arctostaphylos) and four highbush (Vaccinium corymbosum) blueberries fruits (Ivanhoe, Jersey, Northland, and Rekord) were analyzed for total anthocyanins, total phenolics, and antioxidant activity as ferric reducing antioxidant power (FRAP) in this study. The respective ranges of total anthocyanin and total phenolic contents of the tested samples were: blackberries, 0.95–1.97 and 1.73–3.79 mg g⁻¹ and blueberries, 0.18–2.94 and 0.77–5.42 mg g⁻¹. FRAP values varied from 35.05 to 70.41 μmol g⁻¹ for blackberries, 7.41 to 57.92 μmol g⁻¹ for blueberries. Wild blackberries had the highest FRAP values while wild blueberries had the highest total phenolic and total anthocyanin contents. A linear relationship was observed between FRAP values and total phenolics for blueberries (r = 0.981). The anthocyanin pigments in samples were isolated and characterized by high-performance liquid chromatography (HPLC) with UV–visible detection. Cyn-3-glu was the predominant anthocyanin in all blackberry fruits.     

亲水胶体对竹荚鱼鱼糜凝胶特性的影

研究了亲水胶体类型和添加量对竹荚鱼鱼糜凝胶特性的影响.通过对竹荚鱼鱼糜的质构特性、持水力和白度的测定,以及超微结构观察等结果表明,添加可得胶、罗望子胶、魔芋胶、卡拉胶、琼胶和CMC的鱼糜凝胶能形成均匀、致密的三维凝胶网络结构,因此能显著改善竹荚鱼鱼糜的凝胶特性,其中可得胶的效果最显著,其次是罗望子胶、魔芋胶、卡拉胶;添加瓜尔胶和海藻酸钠对竹荚鱼鱼糜的凝胶特性无显著影响;添加黄原胶和果胶后形成了较疏松、网孔较大的网络结构,降低了竹荚鱼鱼糜的凝胶特性.     

DME发动机非常规排放物的检测与分析

用气相色谱仪和傅立叶红外光谱仪对燃用DME的ZS195柴油机的排气中的甲醛(HCHO)、甲酸甲酯(CHCOOCH3)、甲酸(HCOOH)非常规排放物进行了检测和分析。结果表明,DME发动机的尾气排放中,均检测到HCHO,HCOOCH3,HCOOH排放物,且甲醛是非常规排放物中的主要成分,甲醛、甲酸甲酯的排放量随转速上升而略有上升,随负荷增加而不同程度的减少,而甲酸排放量变化则不甚明显。     

超声提取-离子色谱法测定芹菜中氯量

研究了超声提取-离子色谱法测定芹菜中氯含量的方法。芹菜经超声提取20 min后,以浓度4.5 mmol/L Na₂CO₃和0.8 mmol/L NaHCO₃为淋洗液,经IonPacAG23分离测定。本方法具有快速、灵敏、准确度高,适合于芹菜中氯量的测定。     

福建绿衣枳实生药醇提取物的反相HPLC指纹图谱

用RP-HPLC法获得不同绿衣枳实生药的HPLC色谱图,并确定其共有峰,用夹角余弦、相关系数、欧氏距离等不同数理统计方法进行分析。建立福建绿衣枳实生药以33个共有峰为指纹特征信息的对照指纹图谱和质量鉴定分析方法。该方法准确可靠、简便、重现性好,可用于评价不同绿衣枳实生药内在质量。     

The effects of (S)-(+)-carvone treatments on seed potato tuber dormancy and sprouting

Summary Potato seed tubers may suffer from premature sprouting during storage, thus limiting their suitability for cultivation. Commonly used sprout suppressant treatments negatively affect but viability and therefore a reliable method to inhibit bud development must still be found for seed tubers. The monoterpene carvone ((S)-(+)-carvone) was tested in small scale experiments. The vapour of this compound fully inhibited bud growth of tubers cv. Monalisa stored at 23°C without affecting bud viability throughout 6 months of treatment. The most effective range of carvone vapour concentrations was between 0.34 and 1.06 μmol mol⁻¹. With these qualities we can expect carvone to become a suitable sprout suppressant for seed tubers.     

指纹图谱技术在茶叶研究上的应用

茶叶品质难辨易形成混乱的市场局面,制约了茶产业现代化发展进程。近年来,指纹图谱技术在茶叶感官品评、质量控制和产地判别等方面的应用越来越多,为茶叶的品质鉴定提供了有效的技术支撑。文章就茶叶指纹图谱技术方法进行了综述,包括气相色谱(GC)、高效液相色谱(HPLC)、毛细管电泳(CE)、红外(IR)及近红外光谱(NIR)、核磁共振(NMR)等,并对指纹图谱技术在茶叶应用上存在的问题进行了分析,对其今后的发展做出了展望,为指纹图谱技术在茶叶上的进一步应用提供理论基础和参考依据。