Method for the direct detection and/or quantification of at least one compound with a molecular weight of at least 200
The present invention relates to method for the direct detection and/or quantification of at least one compound with a molecular weight of at least 200, wherein the compound to be detected and/or quantified is a chemically complex molecule, wherein said chemically complex molecule is substituted with at least two groups —R, wherein each R group means independently —OH, —OP(O)(OH)2 or —P(O)(OH)2, with the proviso that at least two R are independently selected from —P(O)(OH)2 and —OP(O)(OH)2, wherein the compound or compounds to be detected and/or quantified are within a biological matrix, wherein said biological matrix is a biological fluid, a biological tissue, stomach contents, intestine contents, stool sample or a culture cells, wherein the method comprises performing a chromatography and identifying the retention time and/or the intensity of the signal by means of a mass or radioactivity detector.
1. A method for the direct identification and quantification of at least one phosphorus containing compound having a molecular weight of at least 200 daltons in a biological sample
wherein said biological sample is obtained from a biological fluid selected from the group consisting of blood, plasma, serum, urine, saliva, lymphatic liquid, cerebrospinal fluid and combinations thereof, wherein said biological fluid has been treated with a precipitating agent, a chelating agent, or a combination thereof,
wherein said at least one phosphorus containing compound to be identified and quantified in the biological sample is selected from:
(a) a bisphosphonate or polyphosphonate;
(b) a hexametaphosphate;
(c) a C3-C7 cycloalkyl substituted compound with at least two —R groups wherein each —R group is —OH, —OP(O)(OH) 2 or —P(O)(OH) 2 , and wherein at least two —R groups are independently selected from —P(O)(OH) 2 and —OP(O)(OH) 2 and said C3-C7 cycloalkyl is cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cyclohelptyl;
(d) ions or salts thereof; or,
(e) a combination thereof,
said method comprising:
(i) preparing at least one standard sample of a phosphorus containing compound to be identified and quantified;
(ii) preparing a biological sample containing the at least one phosphorus containing compound to be identified and quantified, wherein the process to prepare said biological sample comprises at least partially or totally dissolving said biological sample to form a solution or a slurry containing the compound;
(iii) introducing the at least one standard sample together or sequentially with the biological sample into a stream of a solvent system, wherein the solvent system is a polar solvent or a solvent mixture comprising at least one polar solvent and passing the samples through at least one chromatography column containing small particles of resin wherein the column is essentially filled of the small particles in a stationary phase while maintaining the pressure of the system in the chromatography column between 5 and 1500 atm;
(iv) identifying the retention time and/or quantifying the intensity of the signal of the at least one phosphorus containing compound to be identified and quantified by means of a mass spectrometry detector when the samples are eluted from the chromatography column;
wherein in said direct identification and quantification of the at least one phosphorus containing compound in said biological sample is not radiolabeled or derivatized.
2. The method according to claim 1 , wherein the C3-C7 cycloalkyl substituted compound is an inositol polyphosphate comprising from 2 to 6 phosphate groups.
3. The method according to claim 2 , wherein the inositol polyphosphate is phytate.
4. The method according to claim 1 , wherein the biological fluid is an isolated sample obtained from a human subject who is under a bioequivalence study.
5. The method according to claim 1 , wherein the method is used to identify and quantify any metabolites of the at least one phosphorus containing compound in a metabolic profile.
6. The method according to claim 1 , wherein the pH of the solvent system is between 7 and 14.
7. The method according to claim 1 , wherein the mass spectrometry detector is a tandem mass spectrometer, a triple quadrupole spectrometer, or a single quadrupole spectrometer.
8. The method according to claim 1 , wherein the mass spectrometry detector operates under selected ion monitoring (SIM) mode, multiple reaction monitoring (MRM) mode, selected reaction monitoring (SRM) mode, SCAN (positive/negative), or a combination thereof.
9. The method according to claim 1 , wherein the standard sample is a reference standard, an external standard, an internal standard, or an standard addition.