Table 1 Operating conditions for the HPLC and ICP-DRC-MS

Solvent A

6 mM Ammonium cabonate

Solvent

20 mM Ammonium phosphate, monobasic

Flow Rate

1.2 mL/min

Column

Anion Exchange, Hamilton PRP-X100, 4.6 mm I.d. × 150 mm, 5 μm

Guard column

2.3 × 30 mm PRP-X100TM

Autosampler flush solvent

5% Methanol

Sample injection volume

50 μL

Inductively coupled plasma- dynamic Reaction Cell- mass

spectrometry (ICP-DRC-MS)

RF Power

1400 W

Monitored Ion m/z

91 (⁷⁵As¹⁶O) for DRC

Detector mode

Dual

Measurement uints

Cps

Autolens

On

Sample units

μg/L

Dwell time

250 ms

Cell gas

High purity O₂ Gas

Cell gas flow rate

0.50 mL/min

RPQ

0.45