Speciation Analysis of Arsenic Compounds by High-Performance Liquid Chromatography in Combination with Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry: Application for Vietnamese Rice Samples

Table 1

Operating conditions of HPLC-ICP-DRC-QMS for speciation of arsenic compounds.

Operating conditions of HPLC-ICP-DRC-QMS
High-performance liquid chromatography operating conditions
Pump	Altus A-30 quaternary pump equipped with solenoid solvent selection valve, online degasser, liquid autosampler with 100 µL injection loop, and column temperature compartment
Column	PRP X 100, 4.6 × 150 mm, 5 μm particle size; Hamilton, NV, USA
Column temperature	Room temperature (app. 25°C)
Eluent	Channel A: 5 mM (NH4)2CO3, pH 9.0, 0, 05% EDTA, 5% MeOH
	Channel B: 50 mM (NH4)2CO3, pH 9.0, 0, 05% EDTA, 5% MeOH
Elution mode	Gradient elution: 0-1 minute: 100% A and then increasing linearly to 100% B in 10 minutes and kept for 4 minutes. Finally decreasing to 100% in 0.1 minutes and kept for 6 minutes to regenerate column
Flow rate	1.0 mL·min^−1
Injection volume	50 μL
ICP-DRC-QMS operating conditions
RF power	1600 W
Plasma gas flow	15 L·min^−1
Auxiliary gas flow	1.2 L·min^−1
Nebulizer gas	1 L·min^−1
Nebulizer	PFA
Spray chamber	Quartz cyclonic
Sample cone	Platinum sample cone
Skimmer cone	Platinum hyper skimmer cone
Cell entrance voltage	−7 V
Cell exit voltage	−7 V
DRC mode	Dynamic reaction cell with oxygen gas, 0.7 mL·min^−1
Monitored ion	AsO^+ (m/z 91)
Measurement mode	Peak hopping
Dwell time	100 ms
RPq	0.6
Quantification mode	External calibration curve