Determination of cadmium in sediment reference materials by isotope dilution inductively coupled plasma mass spectrometry with correction of tin isobaric interference using mass bias equations

2000 ◽  
Vol 15 (5) ◽  
pp. 567-570 ◽  
Author(s):  
Chang J. Park ◽  
Kyung H. Cho ◽  
Jung K. Suh ◽  
Myung S. Han
1993 ◽  
Vol 76 (6) ◽  
pp. 1378-1384 ◽  
Author(s):  
Joseph J Thompson

Abstract A simple method was developed for the accurate and precise determination of low- and sub-ppb (ng/g) concentrations of lead in infant formula by isotope dilution inductively coupled plasma mass spectrometry using ultrasonic nebulization. After addition of a known amount of 207Pb, samples were microwave digested and the ratio 207Pb/208Pb was measured in the digests. Agreement with certified values for lead in milk powder standard reference materials was good, and isotope dilution analysis using 206Pb yielded identical results for the standard reference materials. Lead concentrations determined for several infant nutritional products were verified by an independent method. Typically, relative standard deviations of <4% were obtained with this method for lead concentrations above 2 ppb. The recovery of 2 ng of lead from an aqueous standard carried through the microwave digestion was 104 ± 4%. Infant formula (containing 0.6 ppb lead) to which 0.4 ng of natural-abundance lead had been added, to simulate a formula containing 0.9 ppb lead, was analyzed by isotope dilution, and the result was 96 ± 18% of the theoretical value. Thus, differences of 0.3 ppb lead could be clearly distinguished, and the detection limit was estimated to be 0.1 ng lead per gram of infant formula. The keys to accuracy for this method are minimizing contamination and accurately determining the concentration of lead in the isotopically enriched standard.


2021 ◽  
Vol 7 (3) ◽  
pp. 8-16
Author(s):  
Kim Dung Nguyen Thi ◽  
Thi Lien Nguyen

The determination of 10B/11B isotope ratio and boron concentration in various watersamples using isotope dilution technique with inductively coupled plasma mass spectrometry (ICPMS) was studied. The interferences on precision and accuracy in isotopic ratio determination by ICPMS such as memory effects, dead time, spectral overlap of 12C were investigated for the selection of optimum conditions. By the addition of certain amounts of enriched 10B into samples, the 10B/11B ratio was determined through ICP-MS signal of 10B and 11B. The detection limit for 10B and 11B was experimentally obtained as 0.26 µg/L and 0.92 µg/L, respectively. The ratios of 10B/11B in measured water samples varied in the ranged between 0.1905 and 0.2484 for different matrices. This method has been then applied for the determination of boron isotopic ratio in VVER-1000 reactor-type simulated primary coolant water and in some environmental water samples.


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