Moreno-Cid A, Yebra M C
Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Anal Bioanal Chem. 2004 May;379(1):77-82. doi: 10.1007/s00216-003-2452-6. Epub 2004 Jan 22.
Calcium was extracted on-line from solid seafood samples by a simple and rapid continuous ultrasound-assisted extraction system. This system is connected to a flow injection manifold, which allows the on-line flame atomic absorption spectrometric determination of calcium. This method enables the analysis of solid samples avoiding time-consuming traditional sample preparation methods and their inherent errors. The on-line manifold for calcium determination is the simplest possible, because a volume of 250 microL of acid extract is injected into an ultrapure water carrier stream. The acid extract was diluted on-line with lanthanum, which also acts as masking agent in order to avoid chemical interferences. The continuous monitoring of the calcium signal was accomplished by flame atomic absorption spectrometry. A Plackett-Burman experimental design was used for the optimisation of the continuous leaching procedure. The method allowed a total sampling frequency of 40 samples per hour, with a relative standard deviation for the complete procedure of 0.9% (for a sample containing 3414.35 mg/kg calcium (dry mass)). The limit of detection was found to be 44.4 mg/kg (dry mass) for 5 mg of sample. The analytical procedure was applied to real seafood samples.
采用简单快速的连续超声辅助萃取系统从固体海鲜样品中在线萃取钙。该系统与流动注射歧管相连，可实现钙的在线火焰原子吸收光谱测定。该方法能够对固体样品进行分析，避免了耗时的传统样品制备方法及其固有误差。用于钙测定的在线歧管尽可能简单，因为将250微升酸提取物注入超纯水载流中。酸提取物在线用镧稀释，镧同时作为掩蔽剂以避免化学干扰。通过火焰原子吸收光谱法对钙信号进行连续监测。采用Plackett-Burman实验设计优化连续浸出程序。该方法的总采样频率为每小时40个样品，整个程序的相对标准偏差为0.9%（对于含钙3414.35毫克/千克（干质量）的样品）。对于5毫克样品，检测限为44.4毫克/千克（干质量）。该分析程序应用于实际海鲜样品。
