Aerosol dilution as a simple strategy for analysis of complex samples by ICP-MS

Abstract

This study investigated the capability of High Matrix Introduction (HMI) strategy for analysis of dialysis solution and urine samples using inductively coupled plasma mass spectrometry. The use of HMI enables the direct introduction of urine samples and dialysis solutions 2-fold diluted with 0.14molL HNO. Bismuth, Ge, Ir, Li, Pt, Rh, Sc and Tl were evaluated as internal standards for Al, Ag, As, Be, Cd, Cr, Pb, Sb, Se, Tl, and Hg determination in dialysis solution and As, Cd, Hg and Pb determination in urine samples. Helium collision cell mode (4.5mLmin) was efficient to overcome polyatomic interferences in As, Se and Cr determinations. Mercury memory effects were evaluated by washing with 0.12molL HCl or an alkaline diluent solution prepared with n-butanol, NHOH, EDTA, and Triton X-100. This later solution was efficient for avoiding Hg memory effects in 6h of analysis. Linear calibration curves were obtained for all analytes and detection limits were lower than maximum amounts allowed by Brazilian legislations. Recoveries for all analytes in dialysis solutions and urine samples ranged from 82% to 125% and relative standard deviations for all elements and samples were lower than 7%. Analysis of control internal urine samples was in agreement with certified values at 95% confidence level (t-test; p < 0.05).

Fit-for-Purpose ICP-MS Procedure Supporting Brazilian Regulations on Inorganic Constituents in Fresh and Saline Waters

“…IS was not required for accurate determination of 9 27 Al and 55 Mn probably may be due to the similarity of the mass to charge ratios, m/z, of the IS evaluated with the analytes. 19 However, as demonstrated by Barros et al 18 and also obtained here, significant improvement of recoveries (110 and 118%) were also reached with 193 Ir as IS for 27 Al.…”

“…The use of HMI system (in the same dilution gas flow rate of 0.60 L min -1 ) enabled the direct introduction of urine samples and dialysis solutions 2-fold diluted. 18 Figure 2 shows an increase of oxide formation when increasing NaCl concentration, probably this is due to the decrease of plasma energy caused by plasma loading, in consequence of the presence of sample matrix. However, by increasing HMI gas flow rate (> 0.50 L min -1 ) it was observed that CeO + /Ce + ratio did not vary significantly in most NaCl concentrations.…”

Traditional Calibration Methods in Atomic Spectrometry and New Calibration Strategies for Inductively Coupled Plasma Mass Spectrometry

“…However, as it is common in IS studies, there were some exceptions: 115 In + was the best IS for 50 V + , and 103 Rh + was the best IS for 63 Cu + . Barros et al ( 2018 ) also observed divergences when studying the criteria for selecting the best IS in ICP-MS. They observed improvement in recoveries for 9 Be when 7 Li was used as IS, which may be attributed to the similar mass-to-charge ratios ( m/z ).…”

Direct measurement of multi-elements in high matrix samples with a flow injection ICP-MS: application to the extendedEmiliania huxleyiRedfield ratio

“…Some recent studies reported using an aerosol dilution technique as a simple strategy for the analysis of high matrix samples; 31 , 32 however, they can only measure samples with quite low TDS (less than 3%) and with a relatively large volume (>5 mL sample). For high TDS samples, 33 developed a method using ICP-MS coupled with an ultra-high matrix introduction system (UHMI) to measure Eu and U in highly saline samples (up to 5 mol L –1 NaCl), but such a method requires 100 times on-line dilution for the samples, and therefore is not suitable for analysing elements with low initial concentrations.…”