Dual-mode chemical vapor generation for simultaneous determination of hydride-forming and non-hydride-forming elements by atomic fluorescence spectrometry

Abstract

A dual-mode chemical vapor generation integrating hydride generation and photochemical vapor generation was developed for simultaneous multi-element analysis of hydride-forming and non-hydride-forming elements by atomic fluorescence spectrometry. Four elements were selected as model elements of hydride-forming (As, Cd) and non-hydride-forming (Ni, Fe) elements to validate this proposed method. Standard or sample solutions were separately pumped to mix with tetrahydroborate, and concentrated formic acid and ammonia, and then directed to a hydride generator and a photochemical reactor to realize simultaneous hydride generation and photochemical vapor generation, respectively. Optimum conditions for dual-mode chemical vapor generation were carefully investigated. Under the optimized conditions, limits of detection of 0.05, 0.008, 0.8 and 0.1 μg L(-1) were obtained for As, Cd, Fe and Ni, respectively. The precisions were 5.0, 5.5, 4.3 and 4.5% (n = 6, RSDs) for 2 μg L(-1) of As, 1 μg L(-1) of Cd, 50 μg L(-1) of Fe and 10 μg L(-1) of Ni, respectively. This method was validated for accuracy with three certified reference water samples and applied to the simultaneous determination of these elements in a tap water sample with spike recoveries in the range of 95-99%.

Integration of hydride generation and photochemical vapor generation for multi-element analysis of traditional Chinese medicine by ICP-OES

“…Also, extra heating can be obtained Relatively high PVG efficiency of Ni could be achieved in the pH range of 2.5-3.0, and Co in the relatively broader range of 1.7-2.6. This is well agreed with that reported in the literatures [16,26].…”

“…It has been reported that both Co and Ni achieved the best PVG efficiency in appropriate concentration of formic acid or buffer of formic acid and sodium formate with UV irradiation for 150-180 s [8,[14][15][16]26]. Here, we optimized the experimental conditions for simultaneous PVG of A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 9 Co and Ni.…”

“…It has been reported that the PVG of Ni and Co are partially dependent on the temperature of the photochemical reactant solution, with the best PVG for Co at about 40 ℃ [16] and Ni at 60 ℃ [15]. According to our previous work [26], an online reaction of formic acid with ammonia can take both roles of pH adjustment and heat supply. Also, extra heating can be obtained Relatively high PVG efficiency of Ni could be achieved in the pH range of 2.5-3.0, and Co in the relatively broader range of 1.7-2.6.…”

Ferric ion induced enhancement of ultraviolet vapour generation coupled with atomic fluorescence spectrometry for the determination of ultratrace inorganic arsenic in surface water

“…The UVG-AFS instrumental methods have been applied to many elemental analyses, including conventional hydrideforming elements such as Hg, [17][18][19] Se, [20][21][22] Sn, 23 As, Bi, Sb, Te, 24 Pb, 25 as well as several non-hydride-forming elements, including Fe, Co, Ni, I, and Br. 15,[26][27][28][29][30][31][32] Among them, Gao et al 25 firstly employed inorganic elements (Ni 2+ and Co 2+ ) to enhance the sensitivity of UVG of Pb. For arsenic, Zheng et al employed an UVG reaction of As(III) in acetic acid to obtain the limit of detection (LOD) of 0.5 ng mL −1 .…”

Pump- and Valve-Free Flow Injection Capillary Liquid Electrode Discharge Optical Emission Spectrometry Coupled to a Droplet Array Platform

“…Recently, the miniaturization of analytical instrumentation is making remarkable progress with the development of microelectro-mechanical systems (MEMS), micrototal analysis systems (μ-TAS), and lab-on-a-chip (LOC) technologies. − Over the past two decades, various microplasmas have been developed as promising excitation sources to construct miniaturized OES, including the miniaturized MIP, low-power ICP, capacitively coupled plasma, point discharge, and dielectric barrier discharge (DBD). − Due to the low excitation capacity of microplasma, analytes need to be converted to volatile species and separated from the bulk liquid phase as “dry” species prior to their excitation in the microplasma. ,, Although chemical vapor generation (CVG) can realize effective separation of analyte from liquid phase, it typically remains limited to the determination of several hydride-forming elements . Moreover, CVG techniques (particularly hydride generation, HG) produce a large amount of hydrogen, which significantly disturbs or even extinguishes microplasmas .…”