微波消解-ICP-MS测定美罗培南中铑和钯残留

建立了电感耦合等离子质谱法(ICP-MS)同时测定美罗培南中催化剂铑和钯残留的方法。采用硝酸微波消解处理样品,在合适的ICP-MS条件下测定,铑和钯在1~200μg/L浓度范围内线性关系良好,方法检出限分别为0.7μg/kg和4μg/kg,在三个加标浓度水平,铑的平均回收率为96.7%~99.7%,相对标准偏差为1.0%~2.6%;钯的平均回收率为95.3%~101.9%,相对标准偏差为1.6%~4.4%。本方法操作简便、快捷、灵敏度高,适用于美罗培南中铑和钯残留的检测。     

粉葛全粉加工关键工艺

研究护色和热风干燥关键工艺对粉葛全粉品质的影响。以新鲜粉葛切片的色差值为指标,对氯化钠、抗坏血酸、柠檬酸3种单护色剂进行单因素试验并设计正交试验,得出最佳复合护色剂质量浓度和比例。以总黄酮含量、碘蓝值为指标,利用Box-Behnken响应面分析法对粉葛干燥的工艺参数进行优化。结果表明:粉葛切片最佳复合护色剂组合是2.5%氯化钠、0.4%柠檬酸与0.3%抗坏血酸,协同处理30 min,护色效果最佳;粉葛切片厚度2.5 mm,热风干燥温度、时间分别为56℃与8 h时,制得的粉葛全粉能够有效保留粉葛中的总黄酮、葛根素等功效成分,提高粉葛全粉的品质。     

气相色谱-质谱法测定食品中反式脂肪酸

The trans-fatty acid in foods was determined by GC/MS. The cis-fatty and trans-fatty acids were derivatised as methyl esters using KOH-CH₃OH. The mass fragmentation rule and chromatographic retention time rule of the methyl esters were studied. They were identified with retention time and mass characteristic ions. The method has been applied to determine trans-fatty acid in foods.     

脂肪醇聚氧乙烯醚的电喷雾质谱分析

The mass spectrum rule of the fatty alcohol polyoxyethylene ether(AEO) with different number ethoxy(EO) was discussed by electrospray ionization mass spectrometry(ESI-MS). The main peak of AEO is [M＋Na]^＋ peak, and the response value differ with number of EO. The ionization efficiency is low when the number of EO is high and low, and the ion strength is disproportionate to the concentration of sample, so the value of the number of EO detected should be revised as it is not consistent with actual number. The dimer ＋Na^＋ peak of and trimer＋Na^＋ peak will appear when the concentration of the sample injected or the intensity of the trap ion is high.     

超临界CO2萃取姜油及其成分的GC／MS分析

Essential oil of Curcuma Longal was extracted by SFE CO2, in this article the condition was given. The analysis result by GC/MS showed the essential oil contains 63 constituents, which structure was identified by HP5973MSD. Through this article conclusion was taken that SFE superior to the traditional methods.     

高效液相色谱串联质谱法测定酱油中水解氨基酸

建立了高效液相色谱串联质谱(HPLC-MS/MS)法测定天然酿造酱油原油(FSS)和酸水解植物蛋白调味液(HVP)中多肽的水解氨基酸的组成的方法。FSS多肽总量约是HVP的10倍,其中FSS中多肽的总量为2378.76mg/L,HVP中多肽的总量为247.57mg/L。天然发酵酱油原油中赖氨酸在多肽中的含量21倍高于酸水解植物蛋白液。FSS多肽中赖氨酸、组氨酸、酪氨酸相对百分含量约是HVP的2倍,HVP中丙氨酸、脯氨酸相对百分含量约是FSS的2倍。该研究为鉴别天然酿造酱油与酸水解酱油提供依据。     

酱油香气成分GC/MS分析

用无水乙醚提取酱油中香气成分，GC／MS分离鉴定其化学组成，以面积归一化法测定其相对含量。酱油乙醚萃取物中鉴定出32种化合物，其中对酱油香气成分贡献最大的是HEMF（4-羟基-2（5）-乙基-5（2）-甲基-3（2H）-映喃酮）、4-乙基愈创木酚、香茅醇、5-甲基-2-糖醛及3-甲巯基丙醇等。     

固相微萃取-气相色谱-质谱法对比分析湘菜类地沟油与市售植物油中的挥发性成分

采用固相微萃取结合气相色谱-质谱联用(SPME/GC-MS)技术,对广州市大型湘菜饭店下水道隔油池中的41种地沟油样品和25种市售植物油样品中的挥发性成分进行对比分析,研究表明:地沟油中已确定的挥发性成分113种,植物油中确定的挥发性成分71种。地沟油中醛类与烯烃类挥发性成分种类最多,而植物油中醛类与其它类挥发性成分种类最多;地沟油中酸类物质百分含量最大,而植物油中只含微量的酸类物质;地沟油中含有醚类与芳香类物质,而植物油中未检出;烯烃类中地沟油普遍含有柠檬烯,而植物油中未检出;另外,其它类中地沟油普遍含有大蒜素,而植物油中未检出。因此,可以选择大量酸类、醚类、芳香类、柠檬烯及大蒜素作为湘菜类地沟油的判定成分,为鉴别地沟油与植物油掺假等提供有力的依据。