Extraction of methamphetamine and pseudoephedrine by modified graphene oxide solid phase extraction method coupled to HPLC-UV in urine sample

Table 2 Experiments designed by Box–Behnken method for optimization of methamphetamine (concentration) and pseudoephedrine (concentration) for extraction by Fe₃O₄/C-nanodot

Run	pH	Adsorbent mass (mg)	Time (min)	Solvent	AUC of pseudoephedrine	AUC of methamphetamine
1	8	80	0.1	Methanol	1213	-^a
2	8	50	1.05	Methanol	1624.5	1270
3	4	80	1.05	Methanol	1732.5	1856
4	8	20	2	Methanol	1350	1083
5	4	50	2	Methanol	1671	-^a
6	8	50	1.05	Acetone	1077	1149.5
7	12	20	1.05	Methanol	198.5	1005
8	8	50	1.05	Methanol	721	1414.5
9	12	20	1.05	Acetone	0	980
10	12	80	1.05	Methanol	235.5	2049.5
11	12	50	0.1	Acetone	251.5	1244.5
12	4	50	0.1	Acetone	2407.5	1815.5
13	8	80	2	Methanol	1802	1619.5
14	12	80	1.05	Acetone	298	1642
15	8	50	1.05	Acetone	1077	1149.5
16	4	50	0.1	Methanol	2300.5	1612
17	8	80	2	Acetone	1158.5	1391.5
18	8	20	0.1	Methanol	1000	1691.5
19	4	20	1.05	Acetone	1504.5	-^a
20	8	50	1.05	Methanol	1429.5	1703.5
21	8	80	0.1	Acetone	1213	1073.5
22	4	20	1.05	Methanol	-^a	-^a
23	12	50	2	Acetone	360	-^a
24	8	20	2	Acetone	1885.5	-^a
25	12	50	0.1	Methanol	102	-^a
26	4	80	1.05	Acetone	1176.5	1988
27	4	50	2	Acetone	1193	2458
28	8	50	1.05	Acetone	1077	1149.5
29	8	20	0.1	Acetone	1020.5	1103.5
30	12	50	2	Methanol	196	955.5

ISSN: 2661-801X