Determination of vitamin A in blood serum based on solid‐phase extraction using cetyltrimethyl ammonium bromide‐modified attapulgite

Abstract

Cetyltrimethyl ammonium bromide-modified attapulgite was prepared and utilized as a novel sorbent in a simple solid-phase extraction method for the determination of vitamin A in blood serum. Several factors affecting extraction efficiency were systematically optimized, including the sampling solvent and its volume, as well as the elution solvent and its volume. Under the optimal solid-phase extraction conditions, the adsorption capacity of vitamin A was as high as 28 mg/g according to the Langmuir isotherm model. Based on the developed solid-phase extraction method, the level of vitamin A in 200 µL blood serum sample could be accurately determined by high-performance liquid chromatography. The recoveries of vitamin A spiked in 10% v/v methanol aqueous solutions were in the range of 86.9-92.8%, with the relative standard deviations not more than 8.1%. The method was applied to the determination of vitamin A in serum samples from 20 pregnant women. Compared with the previously reported solid-phase extraction methods for determination of vitamin A in serum, our developed cetyltrimethyl ammonium bromide-modified attapulgite-based solid-phase extraction method used lower serum volume, omitted extra steps (i.e. evaporation and re-dissolution), and eliminated internal standard.The results were promising for it to be used in routine monitoring during pregnancy. K E Y W O R D Sattapulgite, cetyltrimethyl ammonium bromide, serum, solid-phase extraction, vitamin A

Vitamin A Update: Forms, Sources, Kinetics, Detection, Function, Deficiency, Therapeutic Use and Toxicity

“…The retinoid analytic methods described in the literature include (ultra) high-performance liquid chromatography ((U)HPLC) coupled with spectrophotometric (UV-Vis/DAD), spectrofluorimetric (FLD), electrochemical (ECD) detection, mass spectrometry (MS and MS/MS), and also supercritical fluid chromatography (SFC) and immunoassay-based ones, featuring different sensitivities, effectiveness towards different biological matrices, benefits, and limitations. A comparison of these methodologies is provided in Table 2 [ 279 , 280 , 281 , 282 , 283 , 284 , 285 , 286 , 287 , 288 , 289 , 290 , 291 , 292 , 293 , 294 , 295 , 296 , 297 , 298 , 299 , 300 , 301 , 302 , 303 , 304 , 305 , 306 , 307 , 308 , 309 , 310 , 311 , 312 , 313 , 314 , 315 , 316 , 317 , 318 , 319 , 320 , 321 , 322 , 323 , 324 ].…”

“…Whereas single wavelength and DAD are effective for in vitro retinoid assays and quantitation of abundant endogenous retinoids (retinal, retinol, retinoid esters) in vivo, they usually lack the needed sensitivity for making an endogenous bioanalysis of retinoid acid. In fact, concentrations of endogenous ATRA in tissues are up to several orders of magnitude below the limit of detection and/or limit of quantification for both DAD and single-wavelength detection [ 279 , 280 , 281 , 282 , 283 , 284 , 285 , 286 , 287 , 288 , 289 , 290 , 291 , 292 , 293 , 294 , 295 , 320 , 321 , 322 , 323 , 324 ].…”