Methods to increase sensitivity of LC/MS analysis
AssigneeWaters Technologies Corporation
InventorsPaul Rainville, Kerri Smith
Life of this patent
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Abstract
The present disclosure discusses a method of separating a sample (e.g., pharmaceutical drug, genotoxic impurity, biomarker, and/or biological metabolite) including coating a metallic flow path of a chromatographic system; injecting the sample into the chromatographic system; flowing the sample through the chromatographic system; separating the sample; and analyzing the separated sample using mass spectroscopy. In some examples, the coating applied to the surfaces defining the flow path is non-binding with respect to the sample—and the separated sample. Consequently, the sample does not bind to the low-binding surface of the coating of the flow path. The applied coating can increase the chromatographic peak area for the sample of the chromatographic system.
Claims14
A method of separating and analyzing a metal sensitive sample comprising:
- providing a chromatographic system having an alkylsilyl surface coating;
- injecting the sample into the chromatographic system, wherein the sample comprises one or more compounds having a sulfur dioxide constituent;
- flowing the sample through the chromatographic system;
- and
- separating the sample, wherein coating the metallic flow path of the chromatographic system increases a chromatographic peak area of the compounds in the sample of at least 1.6× in comparison to an uncoated chromatographic system having metallic surfaces exposed to fluids.
A method of separating a sample comprising:
- providing a chromatographic system having a metallic flow path with an alkylsilyl coating on fluid exposed surfaces, the metallic flow path with the alkylsilyl coating preventing the sample from binding to underlying metal surfaces;
- injecting the sample into the chromatographic system, wherein the sample comprises one or more compounds having hydroxyl and nitrogen moieties which are in a spatial arrangement that allows the hydroxyl and nitrogen moieties to form chelates with metals;
- flowing the sample through the chromatographic system;
- and
- separating the sample, wherein coating the metallic flow path of the chromatographic system increases a chromatographic peak area of the compounds in the sample of at least 1.6× in comparison to an uncoated chromatographic system having metallic surfaces exposed to fluids.
A method of separating a sample comprising:
- providing a chromatographic system having a metallic flow path with an alkylsilyl coating on fluid exposed surfaces, the metallic flow path with the alkylsilyl coating preventing the sample from binding to underlying metal surfaces;
- injecting the sample into the chromatographic system, wherein the sample comprises N-nitrosodimethylamine (NDMA) and/or N-nitrosodiethylamine (NDEA);
- flowing the sample through the chromatographic system;
- and
- separating the sample, wherein coating the metallic flow path of the chromatographic system increases a chromatographic peak area of the NDMA and NDEA in a sample of at least 1.4× in comparison to an uncoated chromatographic system having metallic surfaces exposed to fluids.
Dependencies are inferred from the claim text.