title: Glyoxal-Urea-Formaldehyde Molecularly Imprinted Resin as Pipette Tip Solid-Phase Extraction Adsorbent for Selective Screening of Organochlorine Pesticides in Spinach.
abstract: A new kind of glyoxal-urea-formaldehyde molecularly imprinted resin (GUF-MIR) was synthesized by a glyoxal-urea-formaldehyde (GUF) gel imprinting method with 4,4'-dichlorobenzhydrol as a dummy template. The obtained GUF-MIR was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) and applied as a selective adsorbent of miniaturized pipet tip solid-phase extraction (PT-SPE) for the separation and extraction of three organochlorine pesticides (dicofol (DCF), dichlorodiphenyl dichloroethane (DDD), and tetradifon) in spinach samples. The proposed pretreatment procedures of spinach samples involved only 5.0 mg of GUF-MIR, 0.7 mL of MeOH-H2O (1:1, v/v) (washing solvent), and 0.6 mL of cyclohexane-ethyl acetate (9:1, v/v) (elution solvent). In comparison with other adsorbents (such as silica gel, C18, NH2-silica gel, and neutral alumina (Al2O3-N)), GUF-MIR showed higher adsorption and purification capacity for DCF, DDD, and tetradifon in aqueous solution. The average recoveries at three spiked levels ranged from 89.1% to 101.9% with relative standard deviations (RSDs) ≤ 7.1% (n = 3). The presented GUF-MIR-PT-SPE method combines the advantages of molecularly imprinted polymers (MIPs), GUF, and PT-SPE and can be used in polar solutions with high affinity and selectivity to the analytes in complex samples.
authors.affiliation: Key Laboratory of Pharmaceutical Quality Control of Hebei Province, Department of Preventive Medicine and Health Management, Hebei University and ‡Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Pharmacy, Hebei University , Baoding 071002, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Yang
authors.affiliation: Key Laboratory of Pharmaceutical Quality Control of Hebei Province, Department of Preventive Medicine and Health Management, Hebei University and ‡Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Pharmacy, Hebei University , Baoding 071002, China.
authors.forename: Tianwei
authors.initials: T
authors.lastname: Lv
authors.affiliation: Key Laboratory of Pharmaceutical Quality Control of Hebei Province, Department of Preventive Medicine and Health Management, Hebei University and ‡Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Pharmacy, Hebei University , Baoding 071002, China.
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Yan
authors.affiliation: Key Laboratory of Pharmaceutical Quality Control of Hebei Province, Department of Preventive Medicine and Health Management, Hebei University and ‡Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Pharmacy, Hebei University , Baoding 071002, China.
authors.forename: Gaochan
authors.initials: G
authors.lastname: Wu
authors.affiliation: Key Laboratory of Pharmaceutical Quality Control of Hebei Province, Department of Preventive Medicine and Health Management, Hebei University and ‡Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, College of Pharmacy, Hebei University , Baoding 071002, China.
authors.forename: Haonan
authors.initials: H
authors.lastname: Li
mesh_terms: D000327:Adsorption; D005506:Food Contamination / Q000032:analysis; D005557:Formaldehyde / Q000737:chemistry; D006037:Glyoxal / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry* / Q000302:isolation & purification; D054802:Molecular Imprinting; D010575:Pesticides / Q000737:chemistry* / Q000302:isolation & purification; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry; D052616:Solid Phase Extraction / Q000295:instrumentation* / Q000379:methods; D018724:Spinacia oleracea / Q000737:chemistry*; D014508:Urea / Q000737:chemistry
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D011108:Polymers; D005557:Formaldehyde; D006037:Glyoxal; D014508:Urea
keywords: glyoxal−urea−formaldehyde gel; molecularly imprinted resin; organochlorine pesticides; pipet tip solid-phase extraction; spinach