Determination of halogens in organic compounds by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS)

Abstract

The feasibility of the determination of sub ppm to percentage levels of halogen elements (fluorine, chlorine, bromine, and iodine) in solid organic compounds and drug substances by double focusing sector field highresolution inductively coupled plasma mass spectrometry (HR-ICP-MS) was investigated. Samples were dissolved in appropriate solvents and then diluted in either deionized water or 5% (v/v) ammonium hydroxide. By applying medium or high resolution, the background counts can be lowered by up to five orders of magnitude compared to conventional quadrupole ICP-MS systems. The signal sensitivities and memory effects of all four elements in different solvents were compared and assessed. The methods were applied to the determination of sub ppm to percentage levels of F, Cl, Br and I in a series of organic compounds and Merck drug substances. The results were found to be in excellent-to-reasonable agreement with the known or theoretical values of these compounds or drug substances. The limit of detection in solution for F was estimated to be 5 mg ml 21 (medium resolution), and for Cl, Br and I was 3 (high resolution), 0.08 (high resolution) and 0.03 (high resolution) ng ml 21 , respectively.

Analysis of Fluorine in Drinking Water by ICP-QMS/QMS with an Octupole Reaction Cell

“…It is notable that the analytical figures of merits obtained in the present work were apparently better that those reported by Bu et al, in which the results were obtained with an HR-ICP-MS by measuring the signal of 19 F + . 5 The sensitivity obtained in the present work was apparently higher (about 77 folds) than that obtained by an HR-ICP-MS, which could be attributed to that the formation of 138 Ba 19 F + in the plasma was much easier than 19 F + .…”

“…The results are summarized in Table 2 along with those reported by other researchers with normal ICP-MS instruments operated under common conditions. 5,11 The BEC was calculated as the concentration equivalent to the signal intensity of It is notable that the technique investigated in the present work is similar to one of the techniques mentioned by Yamada 11 in a feasibility study using test solutions. Detailed optimization of the operating conditions was carried out in the present work, as mentioned above.…”

“…7500 K) 7 due to a higher ionization energy required for fluorine (17.4228 eV) than that for argon (15.7596 eV 5 Okamoto has reported an electrothermal vaporization (ETV-) ICP-MS technique for fluorine analysis, 4 in which the ionization of fluorine was improved by lowering the introduction of water mist into the ICP-MS. Hayashi et al have reported a low-pressure helium ICP-MS for a highly sensitive analysis of fluorine, 6 taking advantage of a higher ionization energy of helium (24.5874 eV) as the plasma gas and improved the ionization of fluorine. Bu et al have reported a technique based on high-resolution (HR-) ICP-MS, 5 in which the isobaric interferences were spectrally separated at a resolution of (m/Δm = ~4000). In addition to the above-mentioned direct measurement of fluorine ion by ICP-MS, there are some studies having reported indirect measurement techniques for fluorine.…”

“…However, there are only several reports about the measurement of fluorine by ICP-MS. [3][4][5][6] There are two major reasons for the difficulty of fluorine measurement by ICP-MS. One reason is that the ionization of fluorine is very difficult, even at extremely high temperature of argon plasma (ca. 7500 K) 7 due to a higher ionization energy required for fluorine (17.4228 eV) than that for argon (15.7596 eV 5 Okamoto has reported an electrothermal vaporization (ETV-) ICP-MS technique for fluorine analysis, 4 in which the ionization of fluorine was improved by lowering the introduction of water mist into the ICP-MS. Hayashi et al have reported a low-pressure helium ICP-MS for a highly sensitive analysis of fluorine, 6 taking advantage of a higher ionization energy of helium (24.5874 eV) as the plasma gas and improved the ionization of fluorine. Bu et al have reported a technique based on high-resolution (HR-) ICP-MS, 5 in which the isobaric interferences were spectrally separated at a resolution of (m/Δm = ~4000).…”

Inductively coupled plasma- and glow discharge plasma-sector field mass spectrometry : Part II. Applications

“…E.g., Bu and co-workers determined the halogens F, Cl, Br and I in pharmaceutical products. 139 They applied medium (F and I) and high (Cl and Br) mass resolution and achieved detection limits for F, Cl, Br and I of 5000, 3, 0.08 and 0.03 ng mL À1 , respectively.…”