Conodont microfossils record seawater strontium isotope values (⁸⁷Sr/⁸⁶Sr), permitting chemostratigraphic correlation for tectonic and climatic reconstructions of the Paleozoic and early Mesozoic (541–201 Ma). Laser ablation multiple collection inductively coupled plasma mass spectrometry (LA MC-ICP-MS) can provide rapid, high spatial resolution ⁸⁷Sr/⁸⁶Sr analysis of conodont bioapatite but has not been validated by comparison with solution analysis. Validation of LA MC-ICP-MS should be completed in order to use the conodont ⁸⁷Sr/⁸⁶Sr values for age-correlations and environmental interpretations. Here, for the first time, we compare solution and LA MC-ICP-MS ⁸⁷Sr/⁸⁶Sr analyses of Carboniferous-age conodonts. Furthermore, we use quadrupole LA ICP-MS to determine concentrations of trace elements potentially responsible for isobaric interferences. Using increased mass resolving power (m/∆m = ~7500) and analyzing conodont tissue with low ⁸⁵Rb/⁸⁸Sr (< 0.001), we find laser ablation copacetic with solution ⁸⁷Sr/⁸⁶Sr values. The two-standard-deviation of these LA ⁸⁷Sr/⁸⁶Sr ratios (average 2SD = 0.00105) are within the two-standard-error uncertainty of solution measurements (average 2SE = 0.00001) on conodonts from the same stratigraphic level. The LA measurements are at a higher spatial resolution and on average 0.00015 higher than solution measurements. Uncertainty of the mean calculations, made on duplicate LA MC-ICP-MS analyses of individual conodonts from the same stratigraphic level, exhibit ⁸⁷Sr/⁸⁶Sr variability beyond the precision of reference materials (2SE = 0.00001). This finding suggests that solution ⁸⁷Sr/⁸⁶Sr values determined by dissolving multiple conodonts are homogenizing the conodont ⁸⁷Sr/⁸⁶Sr signal. As such, the precision of these solution measurements does not capture the geologic variability of conodont ⁸⁷Sr/⁸⁶Sr within a stratigraphic level, which may originate from differential diagenetic alteration. Conodont ⁸⁷Sr/⁸⁶Sr measurements that do not account for this variability are at risk of false calibrations with the paleo-seawater ⁸⁷Sr/⁸⁶Sr curve, which has implications for the timing of geologic events and reconstructions of paleo-environmental changes.

牙形石微化石记录了海水锶同位素值（⁸⁷ Sr / ⁸⁶ Sr），使古生代和中生代（541-201 Ma）的构造和气候重建具有化学地层学相关性。激光烧蚀多收集电感耦合等离子体质谱法（LA MC-ICP-MS）可以对牙形生物磷灰石提供快速，高空间分辨率的⁸⁷ Sr / ⁸⁶ Sr分析，但尚未通过与溶液分析的比较进行验证。为了将牙形石的⁸⁷ Sr / ⁸⁶ Sr值用于年龄相关性和环境解释，应完成LA MC-ICP-MS的验证。在这里，我们第一次比较了溶液和LA MC-ICP-MS ⁸⁷石炭时代牙形石的Sr / ⁸⁶ Sr分析。此外，我们使用四极杆LA ICP-MS确定可能导致同量异位干扰的痕量元素的浓度。使用增加的质量分辨能力（m / ∆ m =〜7500）并分析低⁸⁵ Rb / ⁸⁸ Sr（<0.001）的牙形组织，我们发现激光消融与溶液⁸⁷ Sr / ⁸⁶ Sr值同质。这些LA ⁸⁷ Sr / ⁸⁶的两个标准偏差Sr比（平均值2SD = 0.00105）在相同地层上的牙形石溶液测量值（平均值2SE = 0.00001）的两个标准误差不确定度内。LA测量具有更高的空间分辨率，平均比解决方案测量高0.00015。对来自相同地层的单个牙形石进行重复LA MC-ICP-MS分析得出的平均值计算的不确定性，显示出超出参考材料精度（2SE = 0.00001）的⁸⁷ Sr / ⁸⁶ Sr变异性。这一发现表明，通过溶解多种牙形石确定的溶液⁸⁷ Sr / ⁸⁶ Sr值正在使牙形石⁸⁷ Sr / ⁸⁶均质化Sr信号。因此，这些溶液测量的精度不能捕获地层内牙形石⁸⁷ Sr / ⁸⁶ Sr的地质变化，这可能是由于成岩作用的差异引起的。不能解释这种可变性的牙形石⁸⁷ Sr / ⁸⁶ Sr测量值有可能利用古海水⁸⁷ Sr / ⁸⁶ Sr曲线进行错误标定，这对地质事件的发生时间和古环境变化的重建具有影响。