Simultaneous Determination of Amino Acids and Biogenic Amines in Tuna and Mahi-Mahi by Reversed-Phase Ultra-High Performance Liquid Chromatography

Tuna and mahi-mahi are two major fish species responsible for histamine poisoning. This research developed a rapid ultra-high performance liquid chromatography (UHPLC) method to determine amino acids, histamine, and other biogenic amines that can act as co-indicators of histamine poisoning in tuna and mahi-mahi. The modified UHPLC method could simultaneously determine four biogenic amines and 10 major free amino acids in mahi-mahi (Coryphaena hippurus) and yellowfin tuna (Thunnus albacares) within 17.5 min. This UHPLC method showed good linear response, sensitivity, resolution, recovery, repeatability, and number of theoretical plates. The concentrations of detected amino acids, biogenic amines in mahi-mahi and tuna, and their relationships with fish spoilage grade were determined by this UHPLC method. The developed UHPLC method is a rapid and accurate way to monitor quality changes of mahi-mahi and tuna by inspecting the changes of amino acids and biogenic amines.     

现场胃含物法测定鲐的摄食与生态转换效率

2000年7月至9月在山东半岛南部沿海鲐繁殖海域的鱼类养殖网箱中,应用胃含物法测定了渤海优势鱼种鲐的摄食、生态转换效率等生态能量学参数。结果表明,(1)在饵料不受限制时,鲐的摄食量和生长呈不规则波浪式变化,其波距比较恒定,但波高变化较大;(2)鲐的瞬时胃含物重量随时间变化可用指数模型St=9.0876e-0.1868t描述,瞬时排空率Rt=0.1868g·(100g)-1·h-1(按湿重计算);(3)按Eggers公式可求得鲐日摄食量Cd=(15.60±2.55)g·(100g·d)-1(按湿重计算)或(69.84±11.42)kJ·(100g)-1·d-1;(4)实验期间鲐体重随时间的变化可用线性方程Wt=2.23t+16.71描述,由该式可求得其相对平均日生长量Gd=3.72g·(100g)-1·d-1或30.00kJ·(100g)-1·d-1;(5)由于已知的平均日摄食量和平均日生长量,可求得鲐生态转换效率Eg=23.85%(按湿重计算)或42.96%kJ。     

水产品中氯霉素、甲砜霉素和氟甲砜霉素残留量高效液相色谱-串联质谱内标测定方法的研究

建立了水产品中3种氯霉素类抗生素残留的高效液相色谱-串联质谱(HPLC-MS/MS )测定法.以氘代氯霉素(d5-CAP)为内标,样品在碱性条件下用乙酸乙酯提取,提取液氮气吹干,正己烷液液分配脱脂后,采用配有ESI源的LC-MS/MS选择反应监测(SRM)负离子模式测定,可同时对水产品中的氯霉素、甲砜霉素和氟甲砜霉素进行定性和定量测定.方法简化了样品前处理过程,省去固相萃取步骤,具有操作简便、有机试剂消耗量少、测定周期短和定量更准确等优点.方法的检出限:氯霉素为0.01 μg/kg,甲砜霉素和氟甲砜霉素为0.03 μg/kg.     

水产品中五氯苯酚及其钠盐含量的气相色谱内标测定法

检测水产品中氯苯酚及其钠盐含量的常规方法存在诸多问题, 建立气相色谱内标检测法可以降低乳化、衍生等前处理过程而造成提取物的损失, 增强方法可操作性和准确性, 降低检测的不稳定性, 通过对前处理方法中衍生温度、衍生产物提取液吹干与否对回收率影响的比较研究和色谱条件的改进, 建立了鲫、鳕、日本沼虾、中华绒螯蟹可食部分中五氯苯酚及其钠盐残留量的气相色谱内标法。样品中的五氯苯酚及其钠盐在酸性介质中全部转化为五氯苯酚, 由正己烷提取, 碳酸钾溶液反萃取, 萃取物经乙酸酐衍生生成五氯苯乙酸酯, 正己烷提取衍生物, HP-5MS (30 m×0.25 mm×0.25 μm)色谱柱分离, 用配备微池电子捕获检测器的气相色谱测定, 以2, 4, 6–三溴苯酚作为内标物, 内标法定量。结果表明: 该方法在0.2~20.0 μg/L范围内线性关系良好, 相关系数R2=0.999 6, 在加标水平为2.0、5.0、10.0、50.0 μg/kg, 内标为50.0 μg/kg, 加标回收率为85.8%~109.0%, RSD为0.8%~9.3%, 最低检测限为0.6 μg/kg。