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

Table 2

Mass spectrometry data summary.

Peak (RRT)	Monoisotopic [M + H]^+	Mass accuracy (ppm)	D2O Ex protons	Fragments (m/z)	Proposed structures
0.27 (NM4ABA)	118.0865	2.2	2	100/88
0.67 (NMS)	114.0552	2.1	0	86
0.92 (5-HNMP)	116.0708	1.5	1	73
1.16 (FP)	114.0553	7.0 2.7	1	98
1.33 (2-NEP)	130.0867	3.7	1	112
1.52 (2-AP)	128.0710	3.0	1 (first); 0 (second)	100
1.82 (NEP)	114.0915	1.8	0	100
NMP	100.0758	1.0	0	58

NM4ABA: N-methyl-4-aminobutanoic, NMS: N-methylsuccinimide, 5-HNMP: 5-hydroxy-N-methylpyrrolidone, FP: 1-formyl-2-pyrrolidone, 2-AP: 1-(2-hydroxyethyl)-2-pyrrolidone, 2-NEP: 1-acetyl-2-pyrrolidone, NEP: N-ethylpyrrolidone, and NMP: N-methylpyrrolidone.