Silicon speciation in light petroleum products through the hyphenation of gas chromatography with ICP-tandem mass spectrometry (GC-ICP-MS/MS) is described in the present work. Eleven silicon compounds (nine siloxanes, trimethylsilanol and triethylsilane) have been taken as model molecules. The carrier and optional gas flow rates as well as the hydrogen gas flow rate in the octopole reaction cell (ORC) were critical variables. They precluded both the sensitivity and the extent of the effects caused by the sample matrix and silicon nature. The optimization of the latter variable mitigated the m/z 28 interference (¹⁴N¹⁴N⁺ and ¹²C¹⁶O⁺). Moreover, under the optimized conditions, a universal response was found irrespective of the silicon chemical form and sample matrix. The analytical performances of the method have been evaluated. Thus, the ICP-MS/MS response was linear between 0 and 500 μg kg⁻¹ with correlation coefficients up to 0.999, whereas the limit of quantification (LOQ) ranged from 8 to 60 μg kg⁻¹. Moreover, no drift was found for quality control samples analysed along a given analytical run. Only, the most volatile compound, i.e., trimethylsilanol (TMSOH), induced a drop in sensitivity caused by its partial evaporation from the GC vial. The method was validated by the analysis of real samples and the results were compared with those obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence. No significant differences in Si total content provided by the three methods were found. These results demonstrated that all silicon species were taken into account using GC-ICP-MS/MS as the speciation method. Real light petroleum products, especially coker naphtha samples, were analyzed and it was verified that they only contained cyclic siloxanes (D3–D6), mainly hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane (D4).

中文翻译：

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气相色谱与ICP-MS / MS联用用于轻石油产品中的硅形态分析

在本工作中介绍了通过气相色谱与ICP串联质谱（GC-ICP-MS / MS）联用在轻质石油产品中形成硅的方法。十一种硅化合物（九种硅氧烷，三甲基硅烷醇和三乙基硅烷）已被用作模型分子。八极杆反应池（ORC）中的载气和可选气体流速以及氢气流速是关键变量。他们排除了由样品基质和硅性质引起的敏感性和影响程度。后一个变量的优化减轻了m / z 28干扰（¹⁴ N ¹⁴ N ⁺和¹² C ¹⁶ O ⁺）。此外，在优化的条件下，无论硅的化学形式和样品基质如何，都可以发现通用响应。该方法的分析性能已得到评估。因此，ICP-MS / MS响应在0至500μgkg ^-1之间呈线性，相关系数高达0.999，而定量限（LOQ）在8至60μgkg ^-1之间。而且，在给定的分析过程中分析的质量控制样品没有发现漂移。只有挥发性最高的化合物，即三甲基硅烷醇（TMSOH）引起的灵敏度下降是由于它从GC样品瓶中部分蒸发所致。通过对实际样品的分析验证了该方法，并将结果与​​电感耦合等离子体发射光谱法（ICP-OES）和X射线荧光分析的结果进行了比较。三种方法提供的硅总含量没有显着差异。这些结果表明，使用GC-ICP-MS / MS作为形态分析方法时已考虑了所有硅物种。分析了实际的轻质石油产品，尤其是焦化石脑油样品，并证实它们仅包含环状硅氧烷（D3-D6），主要是六甲基环三硅氧烷（D3）和八甲基环四硅氧烷（D4）。