Abstract: Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.

Abstract: The invention relates to the detection of vitamin D metabolites. In a particular aspect, the invention relates to methods for detecting derivatized vitamin D metabolites by mass spectrometry.

Abstract: Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.

Abstract: Provided herein is A compound of Formula I: or a pharmaceutically acceptable salt thereof, wherein the various substituents are described herein.

Abstract: A media is used to remove species from aqueous solutions, particularly in the treatment of water to enable it to be suitable for drinking. The media includes a material selected from the group consisting of zirconium hydroxide, titanium hydroxide, hafnium hydroxide and combinations thereof. A preferred form of the media is a layer having an aspect ratio of at least 1:1, more preferably, at least about 10:1. Removed from the water are species selected from the group consisting of arsenate, selenate, chromate, borate, perchlorate, fluoride and combinations thereof. In particular arsenite (As+3) containing species are also removed from water. Arsenite may be removed from water to levels not greater than 10 parts per billion with a single exposure to the media. The media is selective for certain species over others.