Determination of Toxic Metals in Little Cigar Tobacco with 'Triple Quad' ICP-MS.

Smoking remains the leading cause of preventable death in the USA. Much of the focus on harmful and potentially harmful constituents (HPHCs) in tobacco products has been on cigarettes. Little cigars gained popularity over the last decade until tobacco taxes made cigarettes more expensive in the USA. Many little cigar brands are similar in size with cigarettes and may be smoked in a similar manner. Scant data are available on HPHC concentrations in little cigars, therefore we developed and applied a new analytical method to determine concentrations of 10 toxic metals in little cigar tobacco. The method utilizes 'triple quadrupole' ICP-MS. By optimizing octapole bias, energy discrimination and cell gas flow settings, we were able to accurately quantify a range of elements including those for which the cell gas reactions were endothermic. All standard modes (Single Quad No Gas, MS-MS NH3/He and MS-MS O2) were utilized for the quantitation of 10 toxic metals in little cigar tobacco, including uranium, which was added as an analyte in the new method. Because of the elimination of interfering ions at 'shifted analyte masses', detection limits were lower compared with a previous method. Tobacco selenium concentrations were below the limit of detection in the previous method, but the new technology made it possible to report all selenium concentrations.

Toxic metal concentrations in mainstream smoke from cigarettes available in the USA.

Public health officials and leaders of 168 nations have signaled their concern regarding the health and economic impacts of smoking by becoming signatory parties to the World Health Organization Framework Convention on Tobacco Control (FCTC). One of FCTC's purposes is to help achieve meaningful regulation for tobacco products in order to decrease the exposure to harmful and potentially harmful constituents (HPHCs) delivered to users and those who are exposed to secondhand smoke. Determining baseline delivery ranges for HPHCs in modern commercial tobacco products is crucial information regulators could use to make informed decisions. Establishing mainstream smoke delivery concentration ranges for toxic metals was conducted through analyses of total particulate matter (TPM) collected with smoking machines using standard smoking regimens. We developed a rapid analytical method with microwave digestion of TPM samples obtained with smoking machines using electrostatic precipitation under the ISO and Intense smoking regimens. Digested samples are analyzed for chromium, manganese, cobalt, nickel, arsenic, cadmium and lead using inductively coupled plasma-mass spectrometry. This method provides data obtained using the ISO smoking regimen for comparability with previous studies as well as an Intense smoking regimen that represents deliveries that fall within the range of human exposure levels to toxic metals.

Determination of chromium species in dietary supplements using speciated isotope dilution mass spectrometry with mass balance.

In order to determine the health impact of chromium in dietary supplements, the Cr(III) and Cr(VI) must be independently measured and verified with mass balance (sum of both species equaling independent measurements of total chromium), as both may be present in finished products. Because Cr(III) is stable in acidic conditions and Cr(VI) in alkaline conditions, interconversions between species may occur in complex matrices and during analytical extraction, increasing the difficulty of quantification. A study was conducted to determine Cr(VI) and Cr(III) in dietary supplements. EPA Method 3060A extraction protocol was performed to extract Cr(VI), and EPA Method 3052 was performed on the extracted residue to digest the remaining Cr(III). Speciated isotope dilution mass spectrometry (SIDMS), as described in the EPA Method 6800 (update V), was implemented with ion-exchange chromatography inductively coupled plasma mass spectrometry (IC-ICP-MS). Method 6800 uniquely enables tracking and correcting for the bidirectional chromium interspecies conversions that occur during extraction and sample handling prior to instrumental analysis. Mass balance results indicated that the off-the-shelf dietary supplements analyzed during this study contained hexavalent chromium ranging from