This manuscript introduces a newly developed method for in situ analysis of bulk water samples, called micro-gas column assisted LIBS (MGC-LIBS). A specially designed MGC assistance system was employed to generate a 1.28 mm diameter stable micro-gas column in situ underwater and laser pulses were focused on the gas-liquid interface of the column to improve LIBS spectral signal of metal elements in water sample. The detection experiments on metal elements in the solution showed that the intensity of ion line in the signal was enhanced by up to 14 times, and the signal RSD value was less than 1%. The detection limits (LOD) of Mg, Ca, Sr, Na, K and Li were all less than 1 mg/L. Compared with the results obtained by direct breakdown experiments in bulk water, the LODs of MGC-LIBS were significantly improved, in which the LOD of Mg element could be reduced by nearly 7.6 times. The concentration calibration curves of the above 6 elements were obtained in the possible concentration ranges of seawater samples, and quantitative inversion experiments were carried out. The results show that the estimated value using MGC-LIBS was basically consistent with the actual value, and the minimum error was 0.12%. This method is expected to be developed into an in situ, online, real-time and highly sensitive detection method for marine investigation or natural water environment monitoring.

该手稿介绍了一种新开发的用于散装水样品原位分析的方法，称为微气柱辅助LIBS（MGC-LIBS）。使用专门设计的MGC辅助系统在水下原位生成直径为1.28 mm的稳定微型气相色谱柱，并将激光脉冲聚焦在色谱柱的气液界面上，以改善水样中金属元素的LIBS光谱信号。溶液中金属元素的检测实验表明，信号中离子线的强度提高了14倍，信号的RSD值小于1％。Mg，Ca，Sr，Na，K和Li的检出限（LOD）均小于1 mg / L。与直接分解实验在散装水中得到的结果相比，MGC-LIBS的检测限得到了显着改善，其中镁元素的LOD可以降低近7.6倍。在可能的海水样品浓度范围内，获得了上述6种元素的浓度校准曲线，并进行了定量反演实验。结果表明，采用MGC-LIBS的估计值与实际值基本一致，最小误差为0.12％。该方法有望被开发成用于海洋调查或自然水环境监测的现场，在线，实时和高度灵敏的检测方法。结果表明，采用MGC-LIBS的估计值与实际值基本一致，最小误差为0.12％。该方法有望被开发成用于海洋调查或自然水环境监测的现场，在线，实时和高度灵敏的检测方法。结果表明，采用MGC-LIBS的估计值与实际值基本一致，最小误差为0.12％。该方法有望被开发成用于海洋调查或自然水环境监测的现场，在线，实时和高度灵敏的检测方法。