Ultra-Performance Liquid Chromatographic Determination of Tocopherols and Retinol in Human Plasma

Bell, Edward C.; John, Mathew; Hughes, Rodney; Pham, Thu Thuy

doi:10.1093/chromsci/bmt161

Cited by 15 publications

(16 citation statements)

References 34 publications

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“…At last, the absorbance of this fraction was measured at 450 nm for carotenoids and 270 nm for tocopherols using a UV–Vis spectrophotometer (Metertech SP8001, Germany). The carotenoids content was calculated as β‐carotene equivalent using extinction coefficient of 2,592 (Rodriguez‐Amaya, ), and the tocopherols content was calculated as α‐tocopherol equivalent using extinction coefficient of 3,270 (Bell, John, Hughes, & Pham, ).…”

Section: Methodsmentioning

confidence: 99%

Effects of age and extraction solvent on phytochemical content and antioxidant activity of fresh Moringa oleifera L. leaves

Nobossé

Fombang

Mbofung

2018

Food Science & Nutrition

114

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Antioxidant activity (AOA) and phytochemical content of Moringa oleifera Lam leaves were determined as a function of their age and extraction solvent. Fresh Moringa leaves aged 30, 45, and 60 days were harvested and extracted with three solvents; methanol, ethanol, and water. AOA of leaf extracts was measured using radical scavenging assays (DPPH, ABTS, antiperoxide activity [APA]) and reducing assays (FRAP and total antioxidant capacity [TAC]), and these were correlated with total polyphenols (TPC), total flavonoids (TFC), and chlorophyll contents of leaves. Significant variability (p < 0.05) in TPC and AOA of Moringa leaf extracts was observed with age and extraction solvent as well as their interaction. TPC and TFC increased with maturity, except in aqueous extract. The 60‐day‐old leaves showed highest TPC, TFC, and tocopherol contents with highest DPPH activity. On their part, 30‐day‐old leaves recorded better vitamin C, chlorophyll, and carotenoids with highest ABTS activity and APA. Methanol was best extraction solvent for TPC (4.6 g GAE/100 g DM) while ethanol was for flavonoids (1.8 g CE/100 g DM). Ethanol extracts exhibited the highest DPPH activity (53.3%–71.1%), while both ethanolic and methanolic extracts had similar and higher ABTS + activity (3.83–3.86 g AAE/100 g DM). Strong positive correlations (r ≥ 0.8; p < 0.05) were observed between chlorophyll content and DPPH, ABTS, and APA, suggesting that chlorophyll was the major contributor to AOA. TAC was highest in aqueous solvent. Free radical scavenging activity in Moringa leaves is positively correlated to chlorophyll, TFC, and TPC while reducing power is positively correlated to chlorophyll and TPC. AOA of fresh Moringa leaf extract is a function of its phytochemical content and is influenced by both the age of the leaves and the extraction solvent used. Methanolic and ethanolic extracts of 45‐day‐old Moringa leaves exhibited best antioxidant potentials.

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Section: Methodsmentioning

confidence: 99%

Effects of age and extraction solvent on phytochemical content and antioxidant activity of fresh Moringa oleifera L. leaves

Nobossé

Fombang

Mbofung

2018

Food Science & Nutrition

114

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“…Many analytical methods to determine the concentrations of retinol and ␣-tocopherol in blood have been reported [19][20][21][22][23][24][25][26][27][28][29][30][31]. Both serum and plasma (EDTA or heparin) have been used, and their vitamins A and E levels were essentially the same [30].…”

Section: Introductionmentioning

confidence: 99%

“…Detection methods include UV, electrochemical, and fluorescence. Only a few of the methods measure ␥-tocopherol [28,29,31]. Some methods also include additional carotenoids, e.g.…”

Section: Introductionmentioning

confidence: 99%

Fast, simple, and sensitive high‐performance liquid chromatography method for measuring vitamins A and E in human blood plasma

Yuan

Burgyan

Bunch

et al. 2014

J of Separation Science

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Vitamins A and E are fat-soluble vitamins that play important roles in several physiological processes. Monitoring their concentrations is needed to detect deficiency and guide therapy. In this study, we developed a high-performance liquid chromatography method to measure the major forms of vitamin A (retinol) and vitamin E (α-tocopherol and γ-tocopherol) in human blood plasma. Vitamins A and E were extracted with hexane and separated on a reversed-phase column using methanol as the mobile phase. Retinol was detected by ultraviolet absorption, whereas tocopherols were detected by fluorescence emission. The chromatographic cycle time was 4.0 min per sample. The analytical measurement range was 0.03-5.14, 0.32-36.02, and 0.10-9.99 mg/L for retinol, α-tocopherol, and γ-tocopherol, respectively. Intr-aassay and total coefficient of variation were <6.0% for all compounds. This method was traceable to standard reference materials offered by the National Institute of Standards and Technology. Reference intervals were established using plasma samples collected from 51 healthy adult donors and were found to be 0.30-1.20, 6.0-23.0, and 0.3-3.2 mg/L for retinol, α-tocopherol, and γ-tocopherol, respectively. In conclusion, we developed and validated a fast, simple, and sensitive high-performance liquid chromatography method for measuring the major forms of vitamins A and E in human plasma.

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“…methanol) to optimize selectivity . Several methods for the determination of lipovitamins in biological fluids involve chromatographic separation using UV–Vis or fluorescence detection (FLD) . The LODs and LOQs of these methods are usually sufficient for the analysis of carotenoids, retinoids, and tocopherols with appropriate precision and accuracy.…”

Section: Fat‐soluble Vitaminsmentioning

confidence: 99%

“…For saponification, KOH or isopropanol are used . For further sample purification, LLE is additionally applied using heptane , hexane , ethyl acetate , chloroform , methyl tert ‐butyl ether , or a mixture of hexane/ethanol/acetone/toluene . Deproteinization and LLE resulted in endogenous compounds of the matrix passing into the supernatant, which may affect the separation and determination of the analytes.…”

Section: Fat‐soluble Vitaminsmentioning

confidence: 99%

A review of chromatographic methods for the determination of water‐ and fat‐soluble vitamins in biological fluids

Karaźniewicz−Łada

Główka

2015

J of Separation Science

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Vitamins are an essential element of nutrition and thus contribute to human health. Vitamins catalyze many biochemical reactions and their lack or excess can cause health problems. Therefore, monitoring vitamin concentrations in plasma or other biological fluids may be useful in the diagnosis of various disorders as well as in the treatment process. Several chromatographic methods have been developed for the determination of these compounds in biological samples, including high-performance liquid chromatography with UV and fluorescence detection. Recently, high-performance liquid chromatography with tandem mass spectrometry methods have been widely used for the determination of vitamins in complex matrices because of their high sensitivity and selectivity. This method requires preconditioning of samples for analysis, including protein precipitation and/or various extraction techniques. The choice of method may depend on the desired cost, convenience, turnaround time, specificity, and accuracy of the information to be obtained. This article reviews the recently reported chromatographic methods used for determination of vitamins in biological fluids. Relevant papers published mostly during the last 5 years were identified by an extensive PubMed search using appropriate keywords. Particular attention was given to the preparation steps and extraction techniques. This report may be helpful in the selection of procedures that are appropriate for certain types of biological materials and analytes.

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Ultra-Performance Liquid Chromatographic Determination of Tocopherols and Retinol in Human Plasma

Cited by 15 publications

References 34 publications

Effects of age and extraction solvent on phytochemical content and antioxidant activity of fresh Moringa oleifera L. leaves

Effects of age and extraction solvent on phytochemical content and antioxidant activity of fresh Moringa oleifera L. leaves

Fast, simple, and sensitive high‐performance liquid chromatography method for measuring vitamins A and E in human blood plasma

A review of chromatographic methods for the determination of water‐ and fat‐soluble vitamins in biological fluids

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