原子吸收法测定包膜复合肥料水浸出液中的钾

用火焰原子吸收法,对两种复合肥料及其包膜肥料水溶出液中的养分钾进行了测定,测试中的6个样品平均加样回收率为107．89％,为包膜复合肥料配方设计和释放特性研究提供了准确、灵敏、快速的定钾方法。     

TSAB─CTMAB分光光度法测定锌合金中微量锑

研究了ＴＳＡＢ、ＣＴＭＡＢ与Ｓｂ（Ⅲ）的反应条件。在ｐＨ３．５～５．２范围内,Ｓｂ（Ⅲ）与ＴＳＡＢ形成稳定的１：２络合物,其最大吸收波长为４７０ｎｍ,摩尔吸光系数为３．１２×１０４。０～９０μｇＳｂ／２５ｍｌ符合比尔定律、用于锌合金中锑的测定,结果满意。     

原子吸收分光光度法中的干扰与抑制

对原子吸收分光光度法中出现的化学干扰、物理干扰和光学干扰及其机理作初步探讨,并列举一些抑制干扰的方法。     

一阶导数分光光度法测定片剂中司帕沙星

建立了用一阶导数分光光度法测定司帕沙星的新方法,该方法具有操作简便、灵敏度高、选择性好等特点,用于测定司帕沙星片剂中司帕沙星的含量,结果令人满意。     

派罗宁B褪色光度法测微量肝素

在pH 4.10的Britton-Robinson缓冲溶液中,肝素与派罗宁B形成离子缔合物,染料发生明显的褪色,体系吸光度的降低与肝素钠浓度成正比,肝素浓度在0～50 μg·(25 mL)-1范围内符合比耳定律.研究了表面活性剂和共存物质的影响,表明方法选择性好.用于肝素钠注射液效价的测定,结果令人满意.     

聚酯切片中钛含量测定的不确定度评定

对分光光度法测定聚酯切片中的钛含量的测定不确定度进行了评定,分析了测定过程中的方法重复性、试样质量、标准滴定溶液、环境温度等方面对不确定度的影响。结果表明,聚酯中钛的质量分数为0．19％,其测定标准不确定度为0．011％,扩展不确定度为0．022％,测定的重复性对测定结果的相对不确定度影响最大。     

Determination of color additive tartrazine (E 102) in food samples after dispersive solid phase extraction with a zirconium-based metal-organic framework (UiO-66(Zr)-(COOH)2)

ABSTRACT

A new and rapid dispersive solid phase extraction method by using a green-synthesised UiO-66(Zr)-(COOH)₂ (Zr-BTeC) adsorbent with body-centred cubic (bcu) topology was developed for determination of tartrazine in food samples. Zr-BTeC was used for the first time as an adsorbent for tartrazine. It was synthesised and characterised by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller surface area analysis, and zeta potential measurements. Tartrazine was determined at 405 nm spectrophotometrically. Experimental conditions were optimised in order to achieve quantitative recoveries. The sample acidity was found to be 0.02 mol L^?1 HCl. The amount of Zr-BTeC was 10 mg. Both adsorption and elution contact times were only 5 s without the need for vortexing. Elution was with 2 mL of 0.5 mol L^?1 NH₃. A sample volume of 45 mL was selected as optimum. The adsorption capacity for tartrazine with Zr-BTeC was found to be 185 mg g^?1 and the adsorbent was reusable up to 40 cycles. The tartrazine concentrations found by the developed method in food supplements were compared with the results obtained by HPLC method for the same samples. Statistical analysis results showed that there are insignificant differences between the results of the two methods (p = .05). The method was successfully applied to the determination of tartrazine in spiked chewing gums, lemon flavoured icing glaze, and jelly samples.     

分光光度法测定桑黄中总黄酮的不确定度评定

目的评定分光光度法测定桑黄中总黄铜的不确定度。方法依据JJF1059.1-2012《测量不确定度评定与表示》的方法,建立相应的数学模型。对测量过程中可能引入不确定度的来源进行分析与计算,进而合成出相对不确定度和扩展不确定度。结果标准曲线是不确定度主要来源,其中曲线拟合所占比例最大。结论在总黄酮测定过程中,要注意选择线性好的标准曲线。     

分光光度法测定磷铁中的锰

对分光光度法测定磷铁中锰含量进行了研究。该方法能快速、简便、准确地检验磷铁样品中锰含量,试验回收率为９９．９３％ ～１００．０１ ％ ,ＲＳＤ％ ＝ １．９３ 。     

混合表面活性剂体系中木素磺酸盐含量的测定

向含木素磺酸盐的混合表面活性剂体系中加入亚硝酸钠和醋酸,再加入氨水显色,在430nm测定吸光度,由工作曲线计算木素磺酸盐含量。讨论了木素衍生化条件对结果的影响以及干扰因素。该方法用于混合表面活性剂中木素磷酸盐或磺化碱木素含量的测定,具有简便、准确的特点。