Dual esi source

HPLC-MS analyses were done with the methods described by [40 (link)] on an Agilent high performance liquid chromatograph (HPLC) 1260 Infinity Series (Agilent Technologies, Santa Clara, CA, USA) coupled to a quadrupole-time of flight (Q-TOF) mass spectrometer model G6540B (Agilent Technologies) with a Dual ESI source (Agilent Technologies). Briefly, 500 μL of a 2 mM solution (in water) of each metal (Cd(ClO₄)₂, CoCl₂, NiCl₂ and Pb(ClO₄)₂) were mixed with 500 μL of harzianic acid (solubilized in methanol, 1 mg·mL⁻¹) and directly infused into the LC-MS system (7 μL injection volumes, eluted with 0.1% formic acid in acetonitrile at a flow rate of 0.3 mL·min⁻¹ to the mass spectrometer). The system was operated in positive ion mode and a standard solution of purine and hexakis(1H,1H,3H-tetrafluoropentoxy)-phosphazene was infused to obtain the real-time lock mass correction. All parameters and acquisitions were set using the Agilent MassHunter Data Acquisition Software, rev. B.05.01 (Agilent Technologies).

Solutions were prepared by mixing 500 µL of 2 mM aqueous solution of each Ln³⁺ cation (Pr³⁺, Eu³⁺, Ho³⁺, Tm³⁺) chloride or perchlorate salts and 500 µL of harzianic acid 1 mg mL⁻¹ in methanol. Then, 7 µL of each sample were injected in an Agilent high-performance liquid chromatography (HPLC) 1260 Infinity Series (Agilent Technologies, Santa Clara, CA, USA) coupled with a quadrupole time-of-flight (Q-TOF) mass spectrometer model G6540B (Agilent Technologies) with a Dual ESI source (Agilent Technologies). The injected volumes were eluted to the mass spectrometer with 0.1% formic acid in acetonitrile at a flow rate of 0.3 mL·min⁻¹. The system operated in positive ion mode and a standard solution of purine and hexakis(1H,1H,3H-tetrafluoropentoxy)phosphazene was infused to obtain the real-time lock mass correction. All parameters and acquisitions were set using the Agilent MassHunter Data Acquisition Software, rev. B.05.01 (Agilent Technologies).

Solutions were prepared by mixing 500 µL of 2 mM solution of each Ln³⁺ cation (La³⁺, Nd³⁺, Sm³⁺, Gd³⁺) and 500 µL of harzianic acid 1 mg mL⁻¹ in methanol. Then, 7 µL of each sample were injected in an Agilent high-performance liquid chromatography (HPLC) 1260 Infinity Series (Agilent Technologies, Santa Clara, CA, USA) coupled with a quadrupole-time-of-flight (Q-TOF) mass spectrometer model G6540B (Agilent Technologies) with a Dual ESI source (Agilent Technologies). The injected volumes were eluted with 0.1% formic acid in acetonitrile at a flow rate of 0.3 mL·min⁻¹ to the mass spectrometer. The system operated in positive ion mode and a standard solution of purine and hexakis(1H,1H,3H-tetrafluoropentoxy)phosphazene was infused to obtain the real-time lock mass correction. All parameters and acquisitions were set using the Agilent MassHunter Data Acquisition Software, rev. B.05.01 (Agilent Technologies).