Alternative sample treatments for the determination of sulfonamides in milk by HPLC with fluorescence detection.
This paper presents two sample treatments, dispersive liquid-liquid microextraction (DLLME) and QuEChERS for the determination of 9 sulfonamides, regulated by the EU Council in milk samples. Both methods represent useful alternatives to conventional procedures based mainly in solid-phase extraction, in terms of simplicity, reduction of organic solvents, sample throughput and effectiveness for cleaning-up complex samples. They have been evaluated and compared in terms of efficiency, trueness, sensitivity and precision, using HPLC with fluorescence detection employing a previous derivatisation step with fluorescamine. Clean extracts were obtained with recoveries between 90.8-104.7% and 83.6-104.8% for DLLME and QuEChERS, respectively. Matrix-matched calibration curves were established for both methods using milk samples spiked at four concentration levels. LODs (3xS/N) lower than 1.21μgL(-)(1) and 2.73μgL(-)(1) for DLLME and QuEChERS, respectively, were obtained in all cases. The precision, in terms of repeatability and intermediate precision, was lower than 10% in all cases.
Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, E-18071 Granada, Spain.
Natalia
N
Arroyo-Manzanares
Laura
L
Gámiz-Gracia
Ana M
AM
García-Campaña
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000302:isolation & purification*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D059627:Liquid Phase Microextraction / Q000379:methods*; D008892:Milk / Q000737:chemistry*; D013449:Sulfonamides / Q000032:analysis* / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents; D013449:Sulfonamides
Dispersive liquid–liquid microextraction; HPLC–FL; Milk; QuEChERS; Sulfonamides