Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université de Lyon, Université Claude Bernard Lyon1, Villeurbanne, France.
Anal Bioanal Chem. 2011 Nov;401(9):2681-9. doi: 10.1007/s00216-011-5079-z. Epub 2011 May 15.
Laser ablation coupled to inductively coupled plasma optical emission spectrometry (LA-ICP-OES) and laser-induced breakdown spectroscopy (LIBS) were investigated for the determination of Ca, Mg, Zn and Na in milk samples. The accuracy of both methods was evaluated by comparison of the concentration found using LA-ICP-OES and LIBS with classical wet digestion associated with ICP-OES determination. The results were not fully acceptable, with biases from less than 1% to more than 60%. Matrix effects were also investigated. The sample matrix can influence the temperature, electron number density (n (e)) and other excitation characteristics in the ICP. These ICP characteristics were studied and evaluated during ablation of eight milk samples. Differences in n (e) (from 8.9 to 13.8 × 10(14) cm(-3)) and rotational temperature (ranging from 3,400 to 4,400 K) occurred with no correlation with trueness. LIBS results obtained after classical external calibration procedure gave degraded accuracy, indicating a strong matrix effect. The LIBS measurements clearly showed that the major problem in LA-ICP was related to the ablation process and that LIBS spectroscopy is an excellent diagnostic tool for LA-ICP techniques.
激光烧蚀与电感耦合等离子体发射光谱（LA-ICP-OES）和激光诱导击穿光谱（LIBS）相结合，用于测定牛奶样品中的 Ca、Mg、Zn 和 Na。通过将 LA-ICP-OES 和 LIBS 法测得的浓度与经典湿法消解结合 ICP-OES 法测定的浓度进行比较，评估了两种方法的准确性。结果并不完全令人满意，偏差从小于 1%到大于 60%不等。还研究了基质效应。样品基质会影响 ICP 中的温度、电子数密度（n(e)）和其他激发特性。在对 8 个牛奶样品进行烧蚀时，研究和评估了这些 ICP 特性。在没有与真实性相关的情况下，n(e)（从 8.9 到 13.8×10(14)cm(-3)）和旋转温度（范围从 3400 到 4400 K）之间存在差异。在经过经典的外部校准程序后，LIBS 结果的准确性降低，表明存在强烈的基质效应。LIBS 测量结果清楚地表明，LA-ICP 中的主要问题与烧蚀过程有关，LIBS 光谱是 LA-ICP 技术的一种极好的诊断工具。
