A pre-column derivatization-high performance liquid chromatographic (HPLC) method has been developed for the determination of histamine in canned fish. The homogenated samples were ultrasonically extracted with perchloric acid aqueous solution, derivatized with dansyl chloride and diluted with acetonitrile to a desired volume. The samples were determined by HPLC with ultraviolet detector and quantified by external standard method. Adopting a C18 column with 1.8 microm stationary phase particles, the analysis time for each sample was smaller than 5 min with the flow rate of 0.3 mL/min. It can decrease the consumption of the mobile phase and save the cost. The linear range was 0.08-8.00 mg/L for histamine. The correlation coefficient was 0.999 98. The average recoveries of histamine at different concentration levels in spiked samples were greater than 96% and the relative standard deviations (RSDs) were smaller than 2.5%. The quantitation limit was 5.00 mg/kg for histamine in canned fish by HPLC. The results indicated that this HPLC method is fast, sensitive, reproducible and practical for the routine analysis of histamine in canned fish.
建立了二十二碳六烯酸标准样品的研制方法.以裂壶藻为原料,利用高速逆流色谱制备分离,通过紫外吸收光谱、红外光谱、质谱和核磁共振等技术对二十二碳六烯酸进行结构确定与表征.标准样品通过高效液相色谱-紫外检测法进行了均匀性、稳定性检验和8家实验室联合定值.结果表明,该标准样品在95%的置信区间内均匀性良好;在4℃条件下可储存9天,在-20℃条件下可储存24个月;定值结果确定其纯度为98.95%,置信度为95%时扩展不确定度为0.17%.该标准样品达到了GB/T 15000.3-2008规定的技术要求,具有溯源性,可用于含有二十二碳六烯酸相关产品的质量控制和含量分析.
采用硝酸+氢氟酸混酸微波密闭消解云母钛珠光颜料样品,以动能歧视-电感耦合等离子体质谱(KED-ICP-MS)法测定砷元素的含量.使用氦气作为碰撞气,利用其与干扰分子间的碰撞裂解作用可显著降低测定时的质谱干扰,选择铑作为内标可有效校正非质谱干扰.通过考察不同氦气流量对砷元素灵敏度和背景等效浓度的影响,优化了碰撞气流量,选择氦流量为3.0 mL/min为最佳检测条件,在此条件下砷元素的质量浓度在0～50 ng/mL范围内与其对应的离子强度校正值线性关系良好,相关系数r>0.999,检出限为0.14 ng/mL.样品测定值的相对标准偏差为4.84%(n=6),两水平加标回收试验砷的回收率为98.3%～102.4%.该方法简便、快捷,为企业对云母钛珠光颜料进行质量控制提供了一种可靠的检测方法.
建立柱前衍生-高效液相色谱法测定脑蛋白水解物中多肽含量的方法.多肽含量为总氨基酸含量与游离氨基酸含量之差.总氨基酸测定水解条件为6 mol/L盐酸溶液于110℃水解20 h.氨基酸测定条件为采用异硫氰酸苯酯作为衍生剂,色谱柱为Agilent Eclipse AAA柱(150 mm×4.6 mm,3.5 μm),柱温为40℃,梯度洗脱.16种氨基酸在质量浓度为1～200 μg/mL的范围内与色谱峰面积线性关系良好,线性相关系数均大于0.99.16种氨基酸的定量限均小于1 μg/mL,精密度和重复性结果均不大于5%,各个技术参数的考察结果均满足检测要求.建立的方法科学可行,适用于脑蛋白水解物多肽含量的控制.
建立了高频红外碳硫仪测定合金钢中的硫元素含量的方法.分别考察了样品质量、助熔剂的种类、叠放次序、空白值对测定结果的影响,确定样品质量为500～1 000 mg,以样品为底层,助熔剂采用中层为钨粒,上层为铁粒的叠放次序,陶瓷坩埚于1 300℃下烘烧2～4 h,可有效避免空白值带来的影响.硫元素质量分数与吸光度线性相关,相关系数为0.999 6,方法检出限为1 μg/g.样品加标回收率为97.4%～100%,测定结果的相对标准偏差为1.81%(n= 10).该方法快速、准确,适用于合金钢中硫元素的测定.
