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Objectives-The purpose was to study the effects on the nervous system in welders exposed to aluminium and manganese. Methods-The investigation included questionnaires on symptoms, psychological methods (simple reaction time, finger tapping speed and endurance, digit span, vocabulary, tracking, symbol digit, cylinders, olfactory threshold, Luria-Nebraska motor scale), neurophysiological methods (electroencephalography, event related auditory evoked potential (P-300), brainstem auditory evoked potential, and diadochokinesometry) and assessments of blood and urine concentrations of metals (aluminium, lead, and manganese). Results-The welders exposed to aluminium (n = 38) reported more symptoms from the central nervous system than the control group (n = 39). They also had a decreased motor function in five tests. The effect was dose related in two of these five tests. The median exposure of aluminium welders was 7065 hours and they had about seven times higher concentrations of aluminium in urine than the controls. The welders exposed to manganese (n = 12) had a decreased motor function in five tests. An increased latency of event related auditory evoked potential was also found in this group. The median manganese exposure was 270 hours. These welders did not have higher concentrations of manganese in blood than the controls. Conclusions-The neurotoxic effects found in the groups of welders exposed to aluminium and manganese are probably caused by the aluminium and manganese exposure, respectively. These effects indicate a need for improvements in the work environments of these welders. (Occup Environ Med 1996;53:32-40)

A high-performance liquid chromatography (HPLC) system with a C 18 column and an aqueous phase eluent (0.08% ammonium acetate and 0.02% L-cysteine) was directly connected to an inductively coupled plasma mass spectrometer (ICP-MS). HPLC-ICP-MS was used to study the abiotic formation of methylmercury, CH 3 Hg 1 , from inorganic mercury, Hg 21 , as well as demethylation of CH 3 Hg 1 to Hg 21 in biological tissues during treatment with tetramethylammonium hydroxide (TMAH) followed by pH adjustment with citric or acetic acid. Enriched isotope standards from CH 3 198 Hg 1 and 201 Hg 21 were added to the samples to monitor species transformation and to apply species-specific isotope dilution (SSID) calibration. Depending on the type of sample matrix, up to 11.5% of added Hg 21 was methylated and up to 6.26% CH 3 Hg 1 was demethylated to Hg 21 . Methylation of Hg 21 probably takes place mainly during and after pH adjustment and it decreases after prolonged TMAH treatment. To minimize abiotic methylation, it is therefore recommended to proceed with pH adjustment after samples have been treated with TMAH for 24 h. There is no significant difference in the degree of methylation using citric or acetic acid.

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Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Species specific isotope dilution calibration for determination of mercury species by gas chromatography coupled to inductively coupled plasma-or furnace atomisation plasma ionisation-mass spectrometry Snell, James P.; Stewart, Ian I.; Sturgeon, Ralph E.; Frech, Wolfgang http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=fr L'accès à ce site Web et l'utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D'UTILISER CE SITE WEB. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=8896562&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=8896562&lang=fr READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://doi.org/10.1039/b007130gJournal of Analytical Atomic Spectrometry, 15, 12, pp. 1540Spectrometry, 15, 12, pp. -1545Spectrometry, 15, 12, pp. , 2000 Full PaperSpecies speci®c isotope dilution calibration for determination of mercury species by gas chromatography coupled to inductively coupled plasma-or furnace atomisation plasma ionisation-mass spectrometry were then used for species speci®c isotope dilution calibration and method assurance tests for mercury species determination. An interface was built to couple a gas chromatograph (GC) to an inductively coupled plasma mass spectrometer (ICP-MS) that resulted in rapid and ef®cient transfer of organic mercury compounds eluted from natural gas condensates. Oxygen, introduced to the plasma auxiliary gas, reduced matrix interferences and improved sensitivity by a factor of two. The GC-ICP-MS method with species speci®c isotope dilution calibration gave recovery values of 97.7¡2.0, 104.1¡0.7 and 106.6¡2.1% for (CH 3 ) 2 Hg, CH 3 HgCl and HgCl 2 , respectively, in natural...

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An on-line amalgamation trap was constructed for the collection of mercury species separated by capillary GC for detection by microwave-induced plasma atomic emission spectrometry. For direct measurement of the column eluate, the detection limits for mercury species in natural gas condensate are elevated because of background interference from carbon compounds passed to the plasma at the same time. Carbon compounds give rise to emission that spectrally interferes with the signal from the mercury detector and can overload the plasma discharge, reducing the excitation capability. With an amalgamation trap, mercury can be selectively collected from the column eluate and subsequently passed to the plasma in a flow of pure helium. By removing the carbon background emission, the trap allows the determination of dimethylmercury in condensate down to a detection limit of 0.24 pg 1-1 and derivatized (butylated) monomethyl and inorganic mercury down to a detection limit of 0.56 pg 1-1 in natural gas condensate. Use of the trap is compared with some existing determination methods for mercury species in condensate and other samples. Solid-phase micro-extraction is used for dimethylmercury, which gives a poorer detection limit of around 20 pg 1-1 because the analyte mass collected is small compared with liquid sample injection. Following derivatization, samples are diluted for direct methylbutylmercury and dibutylmercury determination, corresponding to methylmercury and inorganic mercury. Dilution ensures a reasonably stable background for mercury signals. Again, poorer detection limits of 3.1 and 2.3 pg 1-1, respectively, are obtained owing to the reduced analyte mass. The trap permits the injection of untreated condensate, or condensate reacted with butylmagnesium chloride, into the gas chromatograph without the need for dilution or sample clean-up.