DDL said they believed it was a mono-substituted amine, but no specific identification has been made.

An analytical chemist writes:

Overall, I'm not able to identify the sample from the results of the GC/MS. After looking at it carefully, my best guess is perhaps a substituted amine, perhaps an amphetamine-type molecule.

Many of the larger fragments are consistent with N-ethyl-N-propyl-amphetamine (MW = 205). The fragments that are the most useful though are the ones at 162, 176, 192, and 205. But after some time considering the options, I'm unable to come up with a solution that satisfies the mass spectrum. I can't explain the signal indicated at 192 (its relative abundance is vanishingly small). It differs by 13 mass units from the molecular ion. Some of the lighter fragments are within a proton (1 AMU) of being derivable from putative N-ethyl-N-propyl-amphetamine parent, but the match isn't perfect. Could also get MW = 205 with N-methyl-N-isopropyl-amphetamine, but then there are more fragments that are off by 1-2 AMU.

58.1: This is the strongest signal. called the base peak. Could be -CH(CH3)-NH-CH3, a monomethylated amine. Or it could be -CH2-CH(CH3)-NH2, a nonmethylated amine with a longer side chain. This fragment could indicate either an amphetamine or methamphetamine-type chemical. It could also be -CH(CH3)-N=O.

91: could be benzene ring-CH2-

105: could be benzene ring-CH(CH3)- or benzene ring-CH2-CH2-

121: could be benzene ring-CH(CH3)-NH2 or benzene ring-CH2-CH2-NH2 (phenethylamine)

135: could be benzene ring-CH2-CH(CH3)-NH2 (amphetamine) or benzene ring-CH2-CH2-NH-CH3 (N-methyl-phenethylamine)

149 could be benzene ring-CH2-CH(CH3)-NH-CH3 (methamphetamine)

162: molecular ion loses propyl group(205 - 43 = 162) --> benzene ring-CH2-CH(CH3)-N-CH2-CH3

176: molecular ion loses ethyl group (205 - 29 = 176) --> benzene ring-CH2-CH(CH3)-N-CH2-CH2-CH3

205: molecular ion --> benzene ring-CH2-CH(CH3)-N(CH2CH3)(CH2-CH2-CH3)

March 2, 2015: Finally able to positively ID this as methylone. Thanks Nyak!