Table 3. Compounds Identified by GC-MS/MS in the Product Oil from the Supercritical Water Liquefaction of Polystyrene at Conditions of 450 °C and Final Pressure of 33 MPa with a Residence Time of 60 min and Plastic:Water Ratio of 1:4^a.

retention time (min)	peak area (%)	compound	concentration (mg g–1 of PS)
2.685	0.932	benzene	7.94
4.709	26.399	toluene	224.94
7.162	0.29	cyclohexane, 1-ethyl-1,4-dim	2.47
8.534	38.447	ethylbenzene	327.60
8.933	0.587	p-xylene	5.00
10.092	0.461	styrene	3.93
12.055	12.868	benzene, (1-methylethyl)-/cumene	109.65
13.928	3.544	benzene, propyl-	30.20
14.441	0.214	benzene, 1-ethyl-2-methyl-	1.82
15.004	1.154	benzene, 1,2,3-trimethyl-	9.83
15.837	0.502	α-methylstyrene	4.28
16.633	0.266	benzene, 1,2,4-trimethyl-	2.27
17.726	0.693	benzene, (1-methylpropyl)-	5.90
18.947	0.2	benzene, 2-propenyl-	1.70
20.982	0.643	benzene, butyl-	5.48
26.944	1.054	naphthalene	8.98
30.811	0.736	2-methylnaphthalene	6.27
31.272	0.741	1H-indene, 1-ethylidene-	6.31
33.314	0.262	biphenyl	2.23
34.387	0.252	naphthalene, 1,4-dimethyl-	2.15
34.728	1.046	diphenylmethane	8.91
36.176	1.187	benzene, 1,1′-ethylidenebis-	10.11
36.384	0.341	1,1′-biphenyl, 4-methyl-	2.91
36.647	0.311	4,4′-dimethylbiphenyl	2.65
37.002	1.04	bibenzyl	8.86
38.614	0.504	3,3′-dimethylbiphenyl	4.29
46.82	0.81	2-phenylnapthalene	6.90
49.198	0.236	naphthalene, 2-(phenylmethyl)	2.01
50.123	0.214	m-terphenyl	1.82
62.148	0.311	1,3,5-triphenylbenzene	2.65
total	96.245		820.09

^aListed are the highest concentration compounds identified in the oil.