Preparation of Stable Isotope Standard Samples of Carbon and Nitrogen in Beef Protein
作者单位：Institute of Quality Standard and Testing Technology for Agro-ProductsChinese Academy of Agricultural Sciences
会议名称：《2018年中国质谱学术大会（CMSC2018）》
会议日期：2018年
学科分类：0832[工学-食品科学与工程（可授工学、农学学位）] 08[工学] 083203[工学-农产品加工及贮藏工程]
关 键 词：stable isotope standard sample beef protein
摘 要：Isotope standard samples are essential to enable reliable isotope data. From the beginning of isotopic measurements, there are isotope standard samples. It continues to evolve with the development of isotope research. In this study, two beef proteins have been prepared as standard samples for C and N abundances measurements. First, two kinds of beef samples were collected, followed by diced, ground and freeze-dried for 24 h. Then, the beef samples was extracted with petroleum ether for 6 h in a Soxhlet apparatus. The defatted dry mass of beef was ground in a mortar to pass a 100-mesh sieve. The sieved samples were collected in a trough type mixer and tumbled for 2 h, then was dried in an oven at 50℃ for 4 h to obtain standard samples. The standard samples were sterilized by irradiation and tested for moisture homogeneity and stability tests. The δC and δN values of international reference materials USGS42、USGS43 were measured against the two beef standard samples and common glutamic acid standard samples by stable isotope-ratio mass spectrometry, respectively. It was found that the calibration data of the beef standard sample compared to the common glutamic acid standard sample is closer to the given value of USGS42 and USGS43.