Fractionation of cadmium in tobacco and cigarette smoke condensate using XANES and sequential leaching with ICP-MS/MS

Abstract

Fractionation data for cadmium in tobacco products, as obtained by sequential leaching of cadmium species with ICP-MS/MS analysis, and separately by X-ray absorption near edge structure (XANES) are presented here for the first time. The total amount of cadmium found in 3R4F cigarette cut tobacco was 1526 ± 42 μg kg, of which 5% was found in the smoke under ISO smoking conditions. XANES analysis showed that Cd in tobacco, cigarette smoke and ash was present in the + 2 oxidation state. Examination of the gas-particle partitioning of smoke cadmium suggests that Cd in mainstream smoke is best viewed as semi-volatile, existing in both particulate and gas phases. Sequential extraction of trapped tobacco smoke was carried out to get a deeper insight into the chemistry of cigarette smoke cadmium compounds. Consecutive extractions with ultrapure water, dilute (1%) nitric acid and 10% nitric acid led to extraction of a total amount of Cd which agreed with that obtained after microwave digestion of the whole sample, suggesting that cadmium was quantitatively leachable into aqueous/acidic solutions. Most Cd (~ 90% of the total Cd in the smoke condensate) was extracted into dilute nitric acid (likely as CdO, Cd(OH) and CdCO) with a minor percentage (3%) extracted into water (likely as CdCl) and in 10% nitric acid (likely as CdS). Extraction of trapped mainstream smoke with pentane, followed by ICP-MS/MS analysis, to examine the possible presence of organocadmium in 3R4F tobacco smoke, did not show the presence of organocadmium compounds above the method LOQ (2 μg kg), possibly due to their reactivity under the experimental conditions. The high selectivity with sufficient sensitivity achieved by ICP-MS/MS was invaluable to quantify Cd (at low μg kglevels) simultaneously with sulphur and chlorine in the tobacco smoke fractions of complex matrix. The cadmium chemistry in the smoke, identified in this study, is consistent with both relatively high lung absorption and DNA binding; both potentially important factors for disease progression in smokers. Graphical Abstract This paper provides quantitative fractionation data for cadmium in tobacco and smoke by using sequential leaching with ICPMS and XANES.

Human pluripotent stem cell-derived alveolar epithelial cells are alternatives for in vitro pulmotoxicity assessment

“…We cultured hiPSC-AECs on day 14 of differentiation and BEAS-2B cells in the absence or presence of Cd and investigated their cellular responses compared with primary AECs. According to previous studies, Cd absorption in the lungs depends on the chemical nature of particles deposited 23 . Thus, we used soluble Cd form (cadmium chloride, CdCl 2 ) for the greater toxic potency compared with insoluble Cd compounds such as Cd metal, Cd carbonate (CdCO 3 ) and Cd selenide (CdSe).…”

Inhalation of Trace Metals in Secondhand and Thirdhand Tobacco Smoke Can Result in Increased Health Risks

“…Our emission rate for arsenic, e As = 501 ng cig –1 , is significantly higher than the values reported in the same study (<3.75 and <8.71 ng cig –1 with the ISO and HCI method). A different study reported 76 ng Cd released in mainstream emissions of the experimental 3R4F cigarette under ISO smoking conditions. The observed differences between emissions from smoldering (primarily composed of sidestream smoke) and those reported for mainstream smoke suggest that particle-bound trace metals in mainstream smoke can be efficiently retained by the cigarette’s filter, particularly in the case of arsenic.…”

“…15 However, other studies could not verify the presence of organocadmium in smoke. 16 Similarly, Taebunpakul et al 17 reported that, in unburned cut tobacco, 89% of the total watersoluble arsenic is primarily inorganic As(V) species, and a small amount of the organoarsenic species dimethyl-arsinic acid (DMA) and monomethylarsonic acid (MMA). In watersoluble extracts of mainstream smoke condensate, both arsenate (As(V)) and arsenite (As(III)) were found, suggesting the presence of a reduction process during combustion.…”

Chemical characterization of tobacco-free “modern” oral nicotine pouches and their position on the toxicant and risk continuums

“…First, we derived f EU values based on published data for extraction of nicotine as a bridging compound. However, for compounds that show significantly less extraction than nicotine such as metals (Cuello-Nuñez et al 2018), these estimations should be viewed as conservative. Using reported nicotine extraction of 44-72% for gum NRT (Benowitz et al 1987, Lunell and Lunell 2005a, Lunell and Curvall 2011, Digard et al 2013a, Hansson et al 2019, 30-39% for snus (Lunell and Lunell 2005a, Caraway and Chen 2013, Digard et al 2013a, b, Lunell et al 2020, and 56% and 59% for NPs (Lunell et al 2020), we calculated average f EU values of 0.62, 0.33 and 0.58 for gum, snus and NPs, respectively; in addition, we assumed f EU ¼ 1 for the lozenge NRT, which dissolves completely in the user's mouth.…”