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The effective methylation of phosphonic acids related to chemical warfare agents (CWAs) employing trimethyloxonium tetrafluoroborate (TMO·BF₄) for their qualitative detection and identification by gas chromatography-mass spectrometry (GC-MS) is presented. The methylation occurs in rapid fashion (1 h) and can be conveniently carried out at ambient temperature, thus providing a safer alternative to the universally employed diazomethane-based methylation protocols. Optimization of the methylation parameters led us to conclude that methylene chloride was the ideal solvent to carry out the derivatization, and that even though methylated products can be observed surfacing after only 1 h, additional time was not found to be detrimental but beneficial to the process particularly when dealing with analytes at low concentrations (~10 μg mL^-1). Due to its insolubility in methylene chloride, TMO·BF₄ conveniently settles to the bottom during the reaction and does not produce additional interfering by-products that may further complicate the GC-MS analysis. We demonstrated the method to successfully methylate a variety of Schedule 2 phosphonic acids, including their half esters, resulting in derivatives that were readily detected and identified using the instrument's spectral library. Most importantly, the method was shown to simultaneously methylate a mixture of the organophosphorus-based nerve agent hydrolysis products: pinacolyl methylphosphonate (PMPA), cyclohexyl methylphosphonate (CyMPA) and ethyl methylphosphonate (EMPA) (at a 10 μg mL^-1 concentration each) in a fatty acid ester-rich organic matrix (OPCW-PT-O₃) featured in the 38th Organisation for the Prohibition of Chemical Weapons (OPCW) Proficiency Test. Additionally, the protocol was found to effectively methylate N, N-diethylamino ethanesulfonic acid and N, N-diisopropylamino ethanesulfonic acid that are products arising from the oxidative degradation of the V-series agents VR and VX respectively. This work described herein represents the first report on the use of TMO·BF₄ as a viable, stable and safe agent for the methylation of phosphonic acids and their half esters and within the context of an OPCW Proficiency Test sample analysis.

La arqueometalurgia se constituye, cada vez con mayor fuersa, como un campo de estudio autónomo, dotado de una metodologia propia, que no excluye las contribuciones y aportes de otras disciplinas, pero que si logra configurar un ambiente especifico de investigación. En América la metalurgia antigua ha llamado poderosamente la atención de arquélogos, físicos e ingenieros desde el siglo XIX y su estudio se ha ido abriendo paso, a veces en medio de serias dificultades, hasta la época actual en la cual ya existe una comunidad científíca easi enteramente dedicada a ella. En los congresós de Americanistas de 1984 (Bogotá ) y 1997 (Quito ) los investigadores de la metalurgia prehispánica de América se dieron cita para exponer y comparar sus resultados y demostrar cómo, desde este campo, se puede aportar a la solución de muchos interrogantes de la arquelogía. En el marco del 51 congreso Internacional de Americanistas de Santiago de Chile (2003) se celebró, por tercera vez, un simposio especializado en este tema. Este volumen reúne las contribuciones presentadas por investigadores de Grecia, Argentina, Chile, Perú, Colombia, Estados Unidos, Alemania, Gran Bretaña, Ecuador y Francia.