Grindlay Guillermo, Mora Juan, Maestre Salvador, Gras Luis
Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, PO Box 99, 03080 Alicante, Spain.
Anal Chim Acta. 2008 Nov 23;629(1-2):24-37. doi: 10.1016/j.aca.2008.09.023. Epub 2008 Sep 16.
Elemental wine analysis is often required from a nutritional, toxicological, origin and authenticity point of view. Inductively coupled plasma based techniques are usually employed for this analysis because of their multi-elemental capabilities and good limits of detection. However, the accurate analysis of wine samples strongly depends on their matrix composition (i.e. salts, ethanol, organic acids) since they lead to both spectral and non-spectral interferences. To mitigate ethanol (up to 10% w/w) related matrix effects in inductively coupled plasma atomic emission spectrometry (ICP-AES), a microwave-based desolvation system (MWDS) can be successfully employed. This finding suggests that the MWDS could be employed for elemental wine analysis. The goal of this work is to evaluate the applicability of the MWDS for elemental wine analysis in ICP-AES and inductively coupled plasma mass spectrometry (ICP-MS). For the sake of comparison a conventional sample introduction system (i.e. pneumatic nebulizer attached to a spray chamber) was employed. Matrix effects, precision, accuracy and analysis throughput have been selected as comparison criteria. For ICP-AES measurements, wine samples can be directly analyzed without any sample treatment (i.e. sample dilution or digestion) using pure aqueous standards although internal standardization (IS) (i.e. Sc) is required. The behaviour of the MWDS operating with organic solutions in ICP-MS has been characterized for the first time. In this technique the MWDS has shown its efficiency to mitigate ethanol related matrix effects up to concentrations of 1% (w/w). Therefore, wine samples must be diluted to reduce the ethanol concentration up to this value. The results obtained have shown that the MWDS is a powerful device for the elemental analysis of wine samples in both ICP-AES and ICP-MS. In general, the MWDS has some attractive advantages for elemental wine analysis when compared to a conventional sample introduction system such as: (i) higher detection capabilities; (ii) lower ethanol matrix effects; and (iii) lower spectral interferences (i.e. ArC(+)) in ICP-MS.
从营养、毒理学、产地和真伪鉴定的角度来看，常常需要对葡萄酒进行元素分析。基于电感耦合等离子体的技术通常用于此分析，因为它们具有多元素分析能力和良好的检测限。然而，葡萄酒样品的准确分析很大程度上取决于其基质组成（即盐、乙醇、有机酸），因为它们会导致光谱和非光谱干扰。为了减轻电感耦合等离子体原子发射光谱法（ICP-AES）中与乙醇（高达10% w/w）相关的基质效应，可以成功采用基于微波的去溶剂化系统（MWDS）。这一发现表明MWDS可用于葡萄酒的元素分析。这项工作的目的是评估MWDS在ICP-AES和电感耦合等离子体质谱法（ICP-MS）中用于葡萄酒元素分析的适用性。为了进行比较，采用了传统的进样系统（即连接到雾化室的气动雾化器）。选择基质效应、精密度、准确度和分析通量作为比较标准。对于ICP-AES测量，葡萄酒样品可以直接分析，无需任何样品处理（即样品稀释或消解），使用纯水标准溶液，但需要进行内标法（IS）（即钪）。首次对MWDS在ICP-MS中与有机溶液一起运行的行为进行了表征。在这项技术中，MWDS已显示出其在减轻高达1%（w/w）浓度的与乙醇相关的基质效应方面的效率。因此，必须稀释葡萄酒样品以将乙醇浓度降低到该值以下。所获得的结果表明，MWDS是用于ICP-AES和ICP-MS中葡萄酒样品元素分析的强大设备。一般来说，与传统进样系统相比，MWDS在葡萄酒元素分析方面具有一些吸引人的优点，例如：（i）更高的检测能力；（ii）更低的乙醇基质效应；以及（iii）ICP-MS中更低的光谱干扰（即ArC(+)）。
