1200 series hplc system

Concentrations of monuron, diuron and linuron in in the aqueous phase were analyzed using an Agilent 1200 Series HPLC System with a DAD and an Agilent ZORBAX Eclipse Plus C18 column, 4.6 mm × 250 mm, 5 μm at a flow rate of 0.4 mL min⁻¹ and an injection volume of 5 μL. The ultraviolet DAD was set at 254 nm for diuron, linuron and monuron determination. Isocratic elution was performed with 0.1% formic acid in water and 0.1% formic acid in methanol.
Under these conditions, the elution times were approximately 2.2 min, 3.7 min, and 4.9 min for monuron, diuron, and linuron respectively. Compounds were identified by comparing their retention time values with those of standards. Data was collected and processed using Agilent Chemstation software. The limit of detection for monuron was 1.16 mg L⁻¹, while the limit of detection for diuron was 0.091 mg L⁻¹ for diuron and 0.066 mg L⁻¹ for linuron.

Reagents were purchased from commercial sources without further purification. ¹H NMR, ¹³C NMR, and ³¹P NMR spectra were recorded from a Bruker AdvanceIII 400 (or 500) NMR spectrometer. When using tetrahydrofuran (THF) as the eluent, gel permeation chromatography (GPC) was performed on an Agilent 1260 LC. Molecular weights are versus polystyrene standards. When using trifluoroethanol (TFE) as the eluent, GPC was performed on an Agilent 1200 series HPLC system, using polymethylmethacrylate standards for molecular weight calculation. Dynamic light scattering and zeta potential measurement were measured on a Malvern Zetasizer Nano ZS. Confocal microscopy images were acquired from a Nikon fluorescence microscope equipped with a spectral detector unit. Confocal microscopy video was obtained from a Nikon fluorescence microscope equipped with a Yokogawa spinning disk unit. Flow cytometry experiments were conducted on a ThermoFisher Attune NxT flow cytometer. The infrared spectra were obtained on a Bruker Alpha FT-IR Spectrometer with a spectral range from 3500 cm⁻¹ to 400 cm⁻¹. Thermogravimetric analysis was conducted under N₂ flow from room temperature to 600 °C using a TA Instrument Q50 thermogravimetric analyzer.