Departamento de Química, Avenida Roraima 1000, Universidade Federal de Santa Maria, 97110-970 Santa Maria, RS, Brazil.
Talanta. 2010 Jan 15;80(3):1282-6. doi: 10.1016/j.talanta.2009.09.024.
In this study, oil-in-water formulations were optimized to determine sodium, potassium, calcium, magnesium, zinc, and iron in emulsified egg samples by flame atomic absorption spectrometry (FAAS). This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures and allows the calibration to be carried out using aqueous standards. Different oily phases such as corn oil, decyl oleate and octyl stearate were tested, as well as Tween 80, Triton X-100 and Triton 114 were analyzed as surfactants. The optimum type and proportion of formulations were determined and their use depended on the element studied. The emulsion preparation was performed by a conventional method that involves mixing both phases at 60 degrees C by magnetic stirring and phase inversion to change the water-to-oil ratio by increasing the volume of the surfactant-water external phase and correspondingly decreasing the volume of internal phase. The accuracy of the method was further confirmed by determining the metals in a whole egg powder CRM and recoveries ranged from 97.5% for Mg to 102.2% for Na, with relative standard deviations lower than 2.3%. The precision of the procedures was determined through repeatability (intra-day precision) and intermediate precision (inter-day). The repeatability presented RSD values lower than 4.2%. The intermediate precision was evaluated using the RSD and F-test. The RSD values to intermediate precision was lower than 5.3% and the computed F-values were lower than tabulated F-values, indicating no significant difference between the results obtained on different days. The proposed method including, sample emulsification for subsequent metal determination for FAAS, has proved to be sensitive, reproducible, simple and economical.
本研究通过火焰原子吸收光谱法（FAAS）优化了水包油制剂，以确定乳化鸡蛋样品中的钠、钾、钙、镁、锌和铁。与其他样品预处理程序相比，该方法更简单，所需试剂更少，并且可以使用水溶液标准进行校准。测试了不同的油性相，如玉米油、癸酸油酸酯和十八烷酸辛酯，以及吐温 80、Triton X-100 和 Triton 114 作为表面活性剂。确定了最佳的制剂类型和比例，其使用取决于所研究的元素。乳液的制备是通过常规方法进行的，该方法包括在 60°C 下通过磁力搅拌混合两相，并通过增加表面活性剂-水外部相的体积和相应地减少内部相的体积来改变水油比以实现相反转。通过测定全蛋粉 CRM 中的金属进一步证实了该方法的准确性，回收率范围从 Mg 的 97.5%到 Na 的 102.2%，相对标准偏差低于 2.3%。通过重复性（日内精密度）和中间精密度（日间精密度）来确定程序的精密度。重复性的 RSD 值低于 4.2%。中间精密度是通过 RSD 和 F 检验来评估的。中间精密度的 RSD 值低于 5.3%，计算出的 F 值低于表列的 F 值，表明不同日期获得的结果之间没有显著差异。该方法包括用于 FAAS 后续金属测定的样品乳化，已被证明是灵敏、重现性好、简单且经济的。
