Abstract: The present invention provides methods for utilizing blended compositions of acetonitrile and toluene as organic wash solvents in the production of a synthetic oligonucleotide, the blended compositions producing higher synthetic oligonucleotide yields than a pure acetonitrile wash solvent. The method also provides a process for removing one or more impurities from the acetonitrile and toluene containing wash solvent received as a waste stream from the oligonucleotide synthesis process. The process includes adding at least one of an iodine reactive compound, a sulfur reactive compound and/or an acidic reactive compound to the waste stream, and fractionating the waste stream. The fractionation produces an overhead fraction and a bottom fraction where the overhead fraction includes the acetonitrile and the toluene, and the bottom fraction includes the one or more impurities.

Abstract: A reagent composition for a Karl Fischer titration includes (1) sulfur dioxide or a derivative thereof, (2) a derivative of imidazole, (3) an alcohol, and (4) at least one amino acid that is present in an amount that is greater than zero and up to about 10 weight percent based on a total weight of the reagent composition. Moreover, a molar ratio of the derivative of imidazole to the sulfur dioxide or derivative thereof is greater than 1:1. Iodine is optionally included in a one-component reagent and excluded in a two-component reagent. This disclosure further provides a method for determining an amount of water in a sample via Karl Fischer titration. The method includes the step of providing the sample, providing the reagent composition, which optionally includes the iodine (I2), and titrating the sample with the reagent composition.

Abstract: A reagent composition for a Karl Fischer titration includes (1) sulfur dioxide or a derivative thereof, (2) a derivative of imidazole, (3) an alcohol, and (4) at least one amino acid that is present in an amount that is greater than zero and up to about 10 weight percent based on a total weight of the reagent composition. Moreover, a molar ratio of the derivative of imidazole to the sulfur dioxide or derivative thereof is greater than 1:1. Iodine is optionally included in a one-component reagent and excluded in a two-component reagent. This disclosure further provides a method for determining an amount of water in a sample via Karl Fischer titration. The method includes the step of providing the sample, providing the reagent composition, which optionally includes the iodine (I2), and titrating the sample with the reagent composition.