Table 3.
Respective retention time of compounds identified in 100 normal urine sample
| S. No | Analyte | Trimethylsilyl ester of the compound identified in NIST Library | Retention times (min) | Precursor ion | Daughter ion |
|---|---|---|---|---|---|
| 1 | Propionic acid | Silanol trimethyl propionate | 4.521 | 146 | 131 |
| 2 | Butyric acid | Butanoic acid trimethylsilyl ester | 6.254 | 159 | 144 |
| 3 | Isovaleric acid | Butanoic acid, 3-methyl, trimethylsilyl ester | 6.892 | 159 | 132 |
| 4 | Tiglic acid | 3-Butenoic acid, 3-methyl, trimethylsilyl ester | 8.156 | 172 | 157 |
| 5 | Lactic acid | Propanoic acid, 2-trimethylsilyl-oxy-trimethylsilyl ester | 9.128 | 219 | 191 |
| 6 | Hexanoic acid | Hexanoic acid trimethylsilyl ester | 9.296 | 173 | 132 |
| 7 | Glycolic acid | Acetic acid, [(trimethylsilyl)oxy]-, trimethylsilyl ester | 9.371 | 205 | 177 |
| 8 | Glyoxylic acid | Glyoxylic oxime acid, bis(trimethylsilyl)ester | 10.225 | 233 | 218 |
| 9 | Oxalic acid | Ethanedioic acid bis(trimethylsilyl) ester | 10.295 | 219 | 190 |
| 10 | Pyruvic acid | Pyruvic acid oxime, bis(trimethylsilyl)-deriv. | 10.592 | 247 | 232 |
| 11 | 3Hydroxy isovaleric acid | Butanoic acid, 3-methyl-3(trimethylsilyl)oxy(trimethylsilyl) ester | 11.457 | 247 | 231 |
| 12 | Methylmalonic acid | Propanedioic acid, methyl, bis(trimethylsilyl) ester | 11.554 | 247 | 218 |
| 13 | 2Ethyl,3hydroxypropionic acid | 2Ethyl, 3hydroxypropionic acid, di-TMS | 11.754 | 247 | 233 |
| 14 | Urea | Urea, N,N′-bis(trimethylsilyl)ester | 11.867 | 204 | 189 |
| 15 | Benzoic acid | Benzoic acid trimethylsilyl ester | 11.970 | 194 | 179 |
| 16 | Phosphoric acid | Silanol trimethyl phosphate (3:1) | 12.477 | 314 | 299 |
| 17 | Ethylmalonic acid | Propanedioic acid, ethyl bis(trimethylsilyl) ester | 12.531 | 261 | 217 |
| 18 | Glycerol | Trimethylsilyl ether of glycerol | 12.558 | 293 | 205 |
| 19 | 2Ketoisocaproic acid | 2Ketoisocaproic acid oxime, bis(trimethylsilyl)-deriv. | 12.661 | 274 | 247 |
| 20 | Succinic acid | Butanedioic acid, bis(trimethylsilyl) ester | 13.055 | 262 | 247 |
| 21 | 3-Methylsuccinic acid | Butanedioic acid, methyl, bis(trimethylsilyl) ester | 13.266 | 261 | 186 |
| 22 | Glyceric acid | Propanoic acid, 2,3,bis(trimethylsilyl)oxy-trimethylsilyl ester | 13.434 | 322 | 292 |
| 23 | Fumaric acid | 2-Butenedioic acid(E)-bis(trimethylsilyl) ester | 13.558 | 245 | 217 |
| 24 | 2,3-Dihydroxybutyric acid | (R*S*)-2,3-Dihydroxybutanoic acid, tris(trimethylsilyl) derive. | 13.655 | 321 | 292 |
| 25 | Lactic acid dimer | Lactic acid dimer, bis(trimethylsilyl)- | 14.211 | 291 | 262 |
| 26 | Glutaric acid | pentanedioic acid, bis(trimethylsilyl) ester | 14.325 | 276 | 261 |
| 27 | 3-Methylglutaric acid | Pentanedioic acid, 3-methyl, bis(trimethylsilyl) ester | 14.573 | 275 | 247 |
| 28 | 3-Methyl glutaconic acid | 2-Pentanedioic acid, 3-methyl, bis(trimethylsilyl) ester, (E) | 14.849 | 288 | 273 |
| 29 | Succinylacetone | 5-Methyl-3-isoxazolepropionic acid trimethylsilyl ester | 14.880 | 212 | 182 |
| 30 | 3Phenylbutyric acid | 3Phenylbutyric acid bis trimethylsilyl ester | 14.908 | 236 | 221 |
| 31 | Adipic acid | Hexanedioic acid, bis(trimethylsilyl) ester | 15.405 | 275 | 217 |
| 32 | 3-Methyladipic acid | Hexanedioic acid, 3-methyl, bis(trimethylsilyl) ester | 15.675 | 289 | 186 |
| 33 | Pimelic acid | Heptanedioic acid, bis(trimethylsilyl) ester | 16.226 | 289 | 245 |
| 34 | 4-Hydroxyphenyl acetic acid | Benzeneacetic acid, 4-[(trimethylsily)oxy]-trimethylsilyl ester | 16.529 | 296 | 281 |
| 35 | Suberic acid | Octanedioic acid bis trimethylsilyl ester | 16.981 | 303 | 217 |
| 36 | Orotic acid | 4-Pyrimidine carboxylic acid,2,6-bis(trimethylsily)oxy-trimethylsilyl ester | 17.280 | 372 | 357 |
| 37 | Cis-Aconitic acid | 1-Propene-1,2,3-tricarboxylic acid, tris (trimethylsilyl) ester, [E]- | 17.280 | 375 | 346 |
| 38 | Azelaic acid | Azelaic acid bis trimethylsilyl ester | 17.544 | 317 | 217 |
| 39 | Sebacic acid | Decanedioic acid bis trimethylsilyl ester | 18.095 | 331 | 215 |
| 40 | Hippuric acid | m-Trimethylsilyloxy(trimethylsilyl) hippurate | 19.414 | 399 | 324 |
| 41 | Tropic acid (ISTD)a | Tropic acid trimethylsilyl ester | 16.178 | 280 | 118 |
| 42 | Phenyllactic acid | Benzenepropanoic acid, alpha-[(trimethylsily)oxy]-, trimethylsilyl ester | 16.145 | 295 | 267 |
| 43 | Stearic acid | Octadecanoic acid, trimethylsilyl ester | 19.829 | 356 | 341 |
| 44 | Palmitic acid | Hexadecanoic acid, trimethylsilyl ester | 18.906 | 328 | 313 |
| 45 | Indole acetic acid | 1H-Indole-1-acetic acid,trimethylsilyl ester | 18.349 | 247 | 232 |
| 46 | Phthalic acid | 1,2-Benzenedicarboxylic acid, bis(trimethylsilyl) ester | 16.983 | 310 | 295 |
| 47 | 2,5-Furandicarboxylic acid | 2,5-Furandicarboxylic acid, bis(trimethylsilyl) ester | 16.599 | 300 | 285 |
| 48 | 4-Hydroxyphenylacetic acid | Benzeneacetic acid, 4-[(trimethylsilyl)oxy]-trimethylsilyl ester | 16.567 | 296 | 281 |
| 49 | 2-Furoic acid, 5hydroxymethyl | 2-Furancarboxylic acid,5-[[(trimethylsilyl)oxy)methyl]-, trimethylsily ester | 15.859 | 286 | 271 |
| 50 | Hydroquinone | Silane, [1,4-phenylenebis(oxy)]bis[trimethyl- | 14.368 | 254 | 239 |
| 51 | 2-Keto, 3-methylvaleric acid | 2-Keto-3-methylvalerate oxime,bis[trimethylsilyl]-deriv. | 12.483 | 289 | 274 |
| 52 | Oleic acid | Oleic acid, trimethylsilyl ester | 19.732 | 354 | 339 |
| 53 | Vanillylpropionic acid | Benzenepropionic acid, 3-methoxy-4[(trimethylsilyl)oxy]-, trimethylsilyl | 18.193 | 340 | 325 |
| 54 | Citric acid or isocitric acid | 1,2,3-Propanetricarboxylic acid, 2-[(trimethylsilyl)oxy]-, tris(trimethylsilyl) | 17.804 | 480 | 465 |
| 55 | m-Anisic acid or vanillic acid | Benzoic acid, 3-methoxy-4-[(trimethylsilyl)oxy]-, trimethylsilyl ester | 17.426 | 312 | 297 |
| 56 | Homovanillic acid | Trimethylsilyl[3-methoxy-4-(trimethylsilyloxy)phenyl]acetate | 17.474 | 326 | 311 |
| 57 | Malonic acid | Propanedioic acid, bis(trimethylsilyl) ester | 12.607 | 248 | 233 |
| 58 | 4-Hydroxybutyric acid | Butanoic acid, 4-[(trimethylsilyl)oxy]-, trimethylsilyl ester | 10.787 | 233 | 204 |
| 59 | p-Cresol | Silane, trimethyl(4-methylphenoxy) | 10.581 | 180 | 165 |
| 60 | Ethylene glycol | 1,2-Bis(trimethylsilyloxy)ethane | 7.832 | 206 | 191 |
| 61 | 4-Hydroxyhippuric acid | Glycine, N-[4-(trimethylsilyl)oxy]benzoyl]-,trimethylsilyl ester | 19.819 | 339 | 324 |
| 62 | 2-Hydroxyhippuric acid | Glycine, N-[2-(trimethylsilyl)oxy]benzoyl]-, trimethylsilyl ester | 19.122 | 339 | 324 |
| 63 | 3-Hydroxysebacic acid | 3-Trimethylsiloxysebacic acid, bis(trimethylsilyl)-ester | 19.041 | 419 | 377 |
| 64 | Linolenic acid | Linolenic acid, trimethylsilyl ester | 18.279 | 350 | 335 |
| 65 | 3,5-Dihydroxybenzoic acid | 3,5-Bis(trimethylsiloxy)benzoic acid, trimethylsilyl ester | 17.739 | 370 | 355 |
| 66 | Furoylglycine | Furolglycine, trimethylsilyl ester | 16.696 | 241 | 226 |
| 67 | Pyroglutamic acid | l-Proline,5-oxo-1(trimethylsilyl)-, trimethylsilyl ester; N,O-Bis-(trimethylsilyl)-2-pyrrolidone carboxylic acid | 15.654 | 258 | 230 |
| 68 | 5-Hydroxyhydantoin | Hydantoin, 5-hydroxy-tris-O-(trimethylsilyl)- | 15.621 | 332 | 317 |
| 69 | 2Methyl-3hydroxybutyric acid | Butanoic acid, 2-methyl-3-[(trimethylsilyl)oxy], trimethylsilyl ester | 14.427 | 247 | 218 |
| 70 | Threonolactone | 2(3H)-Furanone,dihydro-3,4-bis[(trimethylsilyl)oxy]-,trans | 14.076 | 262 | 247 |
| 71 | 3-Hydroxyvaleric acid | 5-Trimethylsilyloxy-n-valeric acid, trimethylsilyl ester | 11.181 | 247 | 231 |
| 72 | 4-Hydroxybutyric acid | Butanoic acid, 4-[(trimethylsilyl)oxy], trimethylsilyl ester | 10.786 | 233 | 204 |
| 73 | Acetyltyrosine | N-Acetyltyrosine, di-TMS | 19.397 | 352 | 308 |
| 74 | Ferulic acid | Trimethylsilyl 3-methoxy-4-(trimethylsilyloxy)cinnamate | 19.197 | 338 | 323 |
| 75 | Tartaric acid | Tartaric acid,bis-O-(trimethylsilyl)-,bis(trimethylsilyl) ester | 16.653 | 438 | 423 |
| 76 | Anthranilic acid | Benzoic acid,2-[(trimethylsilyl)amino]-, trimethylsilyl ester | 16.399 | 281 | 266 |
| 77 | 3Hydroxy-3-methylglutaric acid | Pentanedioic acid, 3-methyl-3-[(trimethylsilyl)oxy]-, bis(trimethylsilyl)ester | 16.329 | 363 | 273 |
| 78 | 3-Methylglutaconic acid | 2-Pentenedioic acid, 3-methyl-, bis(trimethylsilyl)ester, (E) | 15.232 | 288 | 273 |
| 79 | 4-Hydroxyphenyllactic acid | Benzenepropionic acid,alpha,4-bis[(trimethylsilyl)oxy]-, trimethylsilyl ester | 18.247 | 398 | 383 |
aInternal standard, not found in biological samples