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US 8,076,157 B2Granted
Vitamin D metabolite determination utilizing mass spectrometry following derivatization
AssigneeQuest Diagnostics Investments Incorporated
InventorsBrett Holmquist, Nigel Clarke, Richard E. Reitz
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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.
Claims81
A method for determining the amount of one or more vitamin D metabolites in a sample by mass spectrometry, the method comprising the steps of
- (i) subjecting the sample to 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) under conditions sufficient to generate one or more PTAD-vitamin D metabolite derivatives;
- (ii) ionizing one or more PTAD-vitamin D metabolite derivatives in the sample to generate one or more ions detectable by mass spectrometry, wherein said ionizing comprises volatilizing said one or more PTAD-vitamin D metabolite derivatives by laser diode thermal desorption;
- (iii) determining the amount of one or more of the PTAD-vitamin D metabolite derivative ions by mass spectrometry;
- and
- (v) relating the amount of PTAD-vitamin D metabolite derivative ions determined in step (iv) to the amount of a vitamin D metabolite in the sample;
- wherein said one or more vitamin D metabolite derivatives are selected from the group consisting of 25-hydroxyvitamin D2 (25OHD2), 25-hydroxyvitamin D3 (25OHD3), 1α,25-dihydroxyvitamin D2 (1α,25(OH)2D2), and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3).
3 more elements
A method for determining the amount of one or more vitamin D metabolites in a sample by mass spectrometry, the method comprising the steps of:
- subjecting one or more 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD)-derivatized vitamin D metabolites in the sample to an extraction column and an analytical column;
- (ii) subjecting one or more PTAD-derivatized vitamin D metabolites in the sample to an ionization source to generate one or more ions detectable by mass spectrometry;
- (iii) determining the amount of one or more of the PTAD-derivatized vitamin D metabolite ions by mass spectrometry;
- and
- (iv) relating the amount of PTAD-derivatized vitamin D metabolite ions determined in step (iii) to the amount of a vitamin D metabolite in the sample,
- wherein the one or more vitamin D metabolites comprise 1α,25-dihydroxyvitamin D2 (1α,25(OH)2D2) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3);
- the sample is subjected to PTAD under conditions sufficient to generate one or more PTAD-derivatized vitamin D metabolites prior to step (i);
- and the extraction and analytical columns of step (i) and the ionization source of step (ii) are connected in an on-line fashion.
5 more elements
A method for determining the amount of one or more vitamin D metabolites in a sample by mass spectrometry, the method comprising the steps of:
- (i) subjecting one or more 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD)-derivatized vitamin D metabolites in the sample to an extraction column and an analytical column;
- (ii) subjecting one or more PTAD-derivatized vitamin D metabolites in the sample to atmospheric pressure chemical ionization (APCI) to generate one or more ions detectable by mass spectrometry;
- (iii) determining the amount of one or more of the PTAD-derivatized vitamin D metabolite ions by mass spectrometry;
- and
- (iv) relating the amount of PTAD-derivatized vitamin D metabolite ions determined in step (iii) to the amount of a vitamin D metabolite in the sample,
- wherein the sample is subjected to PTAD under conditions sufficient to generate one or more PTAD-derivatized vitamin D metabolites prior to step (i).
3 more elements
A method for determining the amount of one or more vitamin D metabolites in a sample by mass spectrometry, the method comprising the steps of:
- (i) subjecting one or more Cookson-derivatized vitamin D metabolites in the sample to an extraction column and an analytical column;
- (ii) subjecting one or more Cookson-derivatized vitamin D metabolites in the sample to an ionization source to generate one or more ions detectable by mass spectrometry;
- (iii) determining the amount of one or more of the Cookson-derivatized vitamin D metabolite ions by mass spectrometry;
- and
- (iv) relating the amount of Cookson-derivatized vitamin D metabolite ions determined in step (iii) to the amount of a vitamin D metabolite in the sample,
- wherein the one or more vitamin D metabolites comprise 1α,25-dihydroxyvitamin D2 (1α,25(OH)2D2) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3);
- the sample is subjected to a Cookson derivatizing reagent under conditions sufficient to generate one or more Cookson-derivatized vitamin D metabolites prior to step (i);
- and the extraction and analytical columns of step (i) and the ionization source of step (ii) are connected in an on-line fashion.
5 more elements
Dependencies are inferred from the claim text.