Strontium/calcium ratios (Sr/Ca) in reef coral skeletons have been used for sea surface temperature (SST) proxy. Because skeletons of reef corals are accumulated throughout more than 100 years, SST records from coral skeletons were important archives to reveal climate mechanisms. Here, we improved the coral Sr/Ca analytical method using an inductively coupled plasma optical emission spectrometer which method has advantages in terms of initial/running cost and analysis time. We checked variations of Sr and Ca sensitivities as increases of Ca concentrations using various wavelengths of Sr and Ca. Our results suggested that sensitivities of Sr/Ca in a range of coral skeletons were modulated by selections of wavelengths and sensitivity changes of Sr and Ca. A combination of Sr(421.5 nm) and Ca(373.6 nm) is stable for the Sr/Ca analysis at a low Ca concentration. A SD of Sr/Ca(421.5/373.6 nm) was 0.006 mmol mol⁻¹ (1σ, n = 40) based on the replicate measurement of the reference material (JCp‐1) using our new method. By applying a Porites colony from Kikai island, Japan, a precision of reconstructed SST was over ± 0.3°C at weekly resolution.

中文翻译：

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使用ICP-OES改进古SST重建珊瑚骨骼中Sr / Ca比的分析方法

珊瑚礁骨骼中的锶/钙比（Sr / Ca）已被用作海表温度（SST）的替代指标。由于珊瑚礁的骨骼是在整个100多年中积累的，因此珊瑚骨骼的SST记录是揭示气候机制的重要档案。在这里，我们改进了使用电感耦合等离子体发射光谱仪的珊瑚Sr / Ca分析方法，该方法在初始/运行成本和分析时间方面均具有优势。我们使用各种波长的Sr和Ca检查了Sr和Ca敏感性随Ca浓度增加而变化的情况。我们的结果表明，通过选择波长和Sr和Ca的敏感性变化，可以调节一系列珊瑚骨骼中Sr / Ca的敏感性。Sr（421.5 nm）和Ca（373。6 nm）对于低Ca浓度的Sr / Ca分析是稳定的。Sr / Ca（421.5 / 373.6 nm）的SD为0.006 mmol摩尔^-1（1σ，n = 40）基于使用我们的新方法对参考材料（JCp-1）的重复测量。通过应用日本Kikai岛的Porites殖民地，以每周分辨率计算，重建SST的精度超过±0.3°C。