Determination of benzalkonium chlorides from wastewater using HPLC-DAD method

This article presents the development and validation of a new high-performance liquid chromatography (HPLC) method coupled with a diode array
detector for the simultaneous analysis of benzalkonium chlorides (benzyl dimethyl
dodecyl ammonium chloride, C12-BZCL, benzyl dimethyl tetradecyl ammonium
chloride, C14-BZCL and benzyl dimethyl hexadecyl ammonium chloride, C16-BZCL)
from wastewater samples. The chromatographic analysis was performed on an
Acclaim Surfactant Plus (150 x 3.0 mm, 3 μm d.p.) column acquired from Thermo
Scientific, kept at 30°C. All experiments were performed in isocratic elution
conditions at a flow-rate of 0.5 mL/min. Mobile phase composition was a mixture of
acetonitrile (A) and 0.2 M ammonium acetate solution (50:50, v/v). UV –VIS detection
was λ = 262 nm for the three BZCL. The limits of detection (LODs) were obtained 15
µg/L (C12- BZCL), 19 µg/L (C14- BZCL) and 25 µg/L (C16- BZCL). The calibration
curves were linear between 1 mg/L - 100 mg/L, with R2 values above 0.999 for all
BZCL. Solid phase extraction (SPE) using polymeric (Strata X) cartridges has been
applied to extract and concentrate the target analytes from the wastewater. BZCL
recoveries after the SPE procedure were situated between 86.0÷94.6%. Intra-day and
inter-day precision (RSD%) were between 1.4 ÷ 2.3% and 6.2 ÷ 6.7%,
respectively. Limits of quantification (LOQs) was 4.5 µg/L (C12-BZCL), 5.6 µg/L
(C14-BZCL) and 7.6 µg/L (C16- BZCL).