Assessing the Oxidative Degradation of N-Methylpyrrolidone (NMP) in Microelectronic Fabrication Processes by Using a Multiplatform Analytical Approach

Figure 5

High resolution mass spectra (MS) and product ion (MS²) spectra of (a) RRT 1.16 (LC/UV platform) observed at m/z 114.0553 Da proposed as 1-formyl-2-pyrrolidone (FP) (mass accuracy of 2.7) with a one dominant daughter ion, at m/z 98.11 Da. (b) RRT 1.82 (LC/UV platform) was proposed as N-ethylpyrrolidone (NEP) (mass accuracy 1.8 ppm) a well-known process impurity. Mass spectrum showed a protonated mass at m/z 114.0915 Da with a MS² spectrum at m/z 100.08 corresponding to a loss of CH₃. (c) RRT 1.52 was proposed as (1-acetyl-2-pyrrolidone, 2-NEP) at m/z 130.0867 Da with a mass accuracy of 3.7 ppm and a main daughter ion at m/z 112.05 corresponding to a neutral loss of carbon monoxide (CO). (d) RRT 1.33 (split peak) was proposed as 1-(2-hydroxyethyl)-2-pyrrolidone (2-AP). Mass spectrum displayed protonated mass at m/z 128.0710 Da and main fragment at m/z 100.09 corresponding to a water loss.

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