백지현 (써모피셔사이언티픽)

백지현 (써모피셔사이언티픽)

Jihyun Paek¹*, Daun Kim¹, Junghyang Lee¹, Minsu Kim¹, Hansun Kwon¹

¹Thermo Fisher Scientific, Gwangpyeong-ro 281, Gangnam-gu, Seoul, Korea, 06349 

Potassium hydroxide (KOH) is a strong alkaline process chemical widely used in semiconductor manufacturing. During manufacturing, storage, and handling, various impurities, including organic acids such as formate, acetate, oxalate, and phthalate, may be introduced into KOH samples. These trace impurities may affect process reliability and product quality. Conventional ion chromatography (IC) relies on retention time and reference standards, limiting the identification of unknown impurities. IC-Orbitrap HRMS provides accurate mass and isotopic pattern information for reliable identification of unknown impurities.

In this study, unknown impurities in KOH samples were qualitatively analyzed using an Auto-Neutralization IC system coupled with an Orbitrap Exploris high-resolution mass spectrometer. After automatic neutralization of the alkaline matrix, analytes were separated by IC and characterized using retention time, accurate mass, and isotopic pattern information.

Various impurities were detected and identified with high confidence. Sulfate and phosphate, despite their nearly identical nominal masses, were clearly distinguished by accurate mass measurements and isotopic pattern analysis. These results demonstrate that IC-Orbitrap HRMS enables reliable qualitative analysis of unknown impurities that are difficult to identify using conventional IC.

The proposed workflow provides an effective platform for impurity profiling and has potential applications in quality control and contamination tracing of high-purity semiconductor process chemicals.