Determination of 14 Metal Impurities in N-Methylpyrrolidone for Integrated Circuits by Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry

A method was proposed for determination of 14 metal impurities in N-methylpyrrolidone (NMP), including Na, Cd, Pb, Mg, Al, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, and K, by triple quadrupole inductively coupled plasma mass spectrometry with the organic additional oxygen sampling system. The impact of carbon deposition on the cone was reduced through oxygen online combustion. The standard addition method was used for matching the matrix effect, and the mass interference from carbon element was eliminated by the cold plasma-ammonia gas collision reaction mode, such as the interferences of ¹²C¹²C⁺ on ²⁴Mg⁺ and ¹²C⁴⁰Ar⁺ on ⁵²Cr⁺. The spiked recoveries of 14 elements were 83.2%-123%, and the correlation coefficients of calibration curves for 14 elements were better than 0.999 0. This method was applied to the analysis of samples with mass fraction less than 20.00 ng·kg^-1, which could meet the quality requirements of advanced production processes.