Speciation of mercury and lead compounds by microbore column liquid chromatography-inductively coupled plasma mass spectrometry with direct injection nebulization

Abstract

Various cationic species of Hg (Hg2+, MeHg+, EtHg+, and PhHg+) and Pb (Pb2+, (Me)3Pb+, and (Et)3Pb+) are separated as Ion pairs by reversed-phase liquid chromatography. Lead Is detected at =0.2 pg and Hg at ~7 pg by Inductively coupled plasma mass spectrometry. A direct Injection nebulizer minimizes band broadening and yields good sensitivity by Injecting all the sample Into the plasma. Chromatographic conditions such as mobile-phase composition and the compound used for Ion pairing are selected based on the mutual requirements of chromatographic performance and detection sensitivity. The Inorganic lone Pb2+ and Hg2+ can be monitored directly In human urine by simply diluting and Injecting the liquid sample. The organolead and organomercury Ions were not concentrated enough to be seen directly In urine, but good separations were obtained when these compounds were spiked Into the sample.

Speciation analysis by small-bore HPLC coupled to ICP-MS

“…Unlike conventional nebulizers, the DIN coupled to micro-bore columns for Cr speciation provides a constant background and improves limits of detection by about 20 times compared with a conventional column [31]. Similar results were found for Pb and Hg speciation [33]. A DIN also shows a good performance to hyphenate UPLC with ICPMS [28].…”

“…Reversed phase C18 columns are indicated to carry out the separation of cobalamins [35]. IP-RP micro-bore HPLC has been applied to perform the separation of various cationic species of Hg and Pb [33] as well as anionic species of As [12] and Se compounds [24,28]. In contrast to normalbore LC-ICPMS, where the use of high organic solvent flow rates has a detrimental effect on the ICP stability, a C18 nanocolumn (150 mm x 75 µm i.d.)…”

“…analyte transport efficiency, low dead volume, improved precision, minimum peak broadening and enhanced sensitivity [33,35].…”

Simple methodology for methylmercury and inorganic mercury determinations by high-performance liquid chromatography–cold vapour atomic fluorescence spectrometry

“…The analytical performance of the methodology proposed in this work was evaluated by the analysis of HPLC-UV-VIS [38,39] 0.10-25 HPLC-CV-AAS [15,40] 80 × 10 −3 to 1.0 HPLC-CV-AAS a [41,42] 20 × 10 −3 to 0.10 HPLC-CV-AFS [16] 20 × 10 −3 HPLC-CV-AFS a [17] 8.0 × 10 −3 HPLC-ACP-AES [19] 70 HPLC-ICP-AES [18] 46 × 10 3 HPLC-CV-ICP-AES [18] 7.4-9.4 HPLC-CV-MIP-AES [43] 35 × 10 −3 HPLC-DIN b -ICP-MS [44] 7.0 × 10 −3 HPLC-USN c -ICP-MS [45] 0.14 HPLC-PN d -ICP-MS [23] 0.70 HPLC-CV-PN d -ICP-MS [13,23] 3.0 × 10 −3 to 60 × a certified reference sediment (CRM 580) using alkaline digestion. Several works have shown concern over the possible formation of MeHg artefacts during certain analytical procedures, such as distillation [46,47] and alkaline dissolution.…”

“…Those values were lower than most of the results reported using other techniques ( Table 4). The lowest DLs are reported when preconcentration coupled to a CV-AFS detector [17] and ICP-MS with a direct injection nebulizer [44] or cold vapor generation [13] was used. The DL obtained in this work is about half of the value reported by Hintelmann and Wilken [16], with a similar detection system.…”