采用扩散皿吸收-盐酸滴定法测定牡丹花籽的蛋白质含量法.牡丹籽粉末在10 mL浓硫酸、0.2 g CuSO4和6.0 g K2SO4的条件下电炉加热碳化.扩散皿内室是3 mL 20 g/L的硼酸吸收液,移取5 mL消化液于扩散皿外室,加入10 mL浓度400 g/L的NaOH溶液,盖上皿盖,置于烘箱内24 h.用盐酸滴定硼酸吸收液.硫酸铵为标准液,其浓度在10~200 μg/mL线性范围良好,相关系数R2=0.9966,添加回收率74.62%~106.07%,相对标准偏差0.27%~2.88%,4种牡丹籽的蛋白质含量为10%~14%,与国标的凯氏定氮法对比,平均差异为0.84%.该方法具有良好的稳定性、可重复性,操作简单,用于蛋白质的批量检测,可提高检测效率.%A simple and reliable preparation method with conway diffusion absorption and muriatic acid ti-tration detection for mass determination protein in the peony seeds has been established.Under catalyst (0.2 g CuSO4and 6.0 g K2SO4)in electric hot plate with 10 mL concentrated sulfuric acid to heat,then took 5 mL extracts and 10 mL 400 g/L sodium hydroxide in diffusion cell,3 mL 20 g/L boric acid absorp-tion in the inner chamber and then covered with cap.Afterwards keep it in the oven for 24 h,finally,titra-tion with a known concentration muriatic acid.It's results was about 0.84%significant difference compare with Kjeldah method.The linear calibration ranges of ammonium sulfate were within 10~200 μg/mL,the results showed good linearity(R2=0.999 6).Average recoveries were 74.62%~106.07%,the corre-sponding relative standard deviations were 0.27%~2.88%.It was demonstrated that the proposed method was good repeatability,stable and particularly suitable for detecting protein of the peony seeds in batches.
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