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.

Provided are methods of detecting the presence or amount of a dihydroxyvitamin D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a dihydorxyvitamin 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. In certain preferred embodiments the methods include immunopurifying the dihydroxyvitamin D metabolites prior to mass spectrometry. Also provided are methods to detect the presence or amount of two or more dihydroxyvitamin D metabolites in a single assay.

A reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein and an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition as well as the reagent mixture obtained in this manner. Also disclosed is the use of the reagent compositions to release vitamin D compounds as well as a kit for detecting a vitamin D compound.

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.

Methods for determining the amount of vitamin D compounds in a sample are provided. The methods can employ LC-MS/MS techniques and optionally the use of deuterated internal standards. Methods for diagnosing vitamin D deficiencies are also provided.

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.

A reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein and an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition as well as the reagent mixture obtained in this manner. Also disclosed is the use of the reagent compositions to release vitamin D compounds as well as a kit for detecting a vitamin D compound.

An improved analytical method for analysis of dianhydrogalactitol preparations provides a method for determining the purity of dianhydrogalactitol and detecting impurities in preparations of dianhydrogalactitol, as well as identifying any such impurities. The method employs high performance liquid chromatography (HPLC), in particular, HPLC with evaporative light scattering detection (ELSD); the HPLC can be followed by tandem mass spectroscopy. The method can further comprise the step of performing preparative HPLC collection of at least one specific substance peak present in a preparation of dianhydrogalactitol.

Provided are methods of detecting the presence or amount of a dihydroxyvitamin D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a dihydorxyvitamin 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. In certain preferred embodiments the methods include immunopurifying the dihydroxyvitamin D metabolites prior to mass spectrometry. Also provided are methods to detect the presence or amount of two or more dihydroxyvitamin D metabolites in a single assay.

A reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein and an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition as well as the reagent mixture obtained in this manner. Also disclosed is the use of the reagent compositions to release vitamin D compounds as well as a kit for detecting a vitamin D compound.