Solving matrix-effects exploiting the second order advantage in the resolution and determination of eight tetracycline antibiotics in effluent wastewater by modelling liquid chromatography data with multivariate curve resolution-alternating least squares

MD GIL GARCÍA; MJ CULZONI; MM DE ZAN; R SANTIAGO VALVERDE; M MARTINEZ GALERA; HC GOICOECHEA

JOURNAL OF CHROMATOGRAPHY - A

Año: 2008 vol. 1179 p. 115 - 124

0021-9673

AbstractA new powerful algorithm (unfolded-partial least squares followed by residual bilinearization (U-PLS/RBL)) was applied for first time onsecond-order liquid chromatography with diode array detection (LC–DAD) data and compared with a well-known established method (multivariatecurve resolution-alternating least squares (MCR-ALS)) for the simultaneous determination of eight tetracyclines (tetracycline, oxytetracycline,meclocycline, minocycline, metacycline, chlortetracycline, demeclocycline and doxycycline) in wastewaters. Tetracyclines were pre-concentratedusing Oasis Max C18 cartridges and then separated on a Thermo Aquasil C18 (150mm×4.6 mm, 5 m) column. The whole method was validatedusing Milli-Q water samples and both univariate and multivariate analytical figures of merit were obtained. Additionally, two data pre-treatmentwere applied (baseline correction and piecewise direct standardization), which allowed to correct the effect of breakthrough and to reduce thetotal interferences retained after pre-concentration of wastewaters. The results showed that the eight tetracycline antibiotics can be successfullydetermined in wastewaters, the drawbacks due to matrix interferences being adequately handled and overcome by using U-PSL/RBL.