scholarly journals Analysis of Vitamin A in Multivitamin Products

Author(s):  
A. S. Alekseeva ◽  
T. B. Shemeryankina ◽  
M. N. Lyakina ◽  
M. S. Smirnova ◽  
E. P. Fedorova ◽  
...  

Vitamin A is present in multivitamin products mainly in the form of retinol esters: retinyl acetate, retinyl palmitate, and beta carotene—retinol precursor (dimer) found in plants, which is capable of converting into retinol in liver cells. Retinol is determined in medicinal products primarily by high performance liquid chromatography (HPLC), with preliminary purification and vitamin isolation by liquid-liquid extraction. However, scientific literature also describes other methods of sample preparation and analysis of such compounds. An important issue is differentiation of vitamin A from other fat-soluble vitamins often included as components in multivitamin products. The aim of the study was to analyse and summarise data on current methods used for determination of vitamin A and its derivatives in medicinal products. The authors analysed the range of vitamin A products authorised in the Russian Federation, and the test methods described in their product specification files. The study demonstrated that the test method most often used for determination of retinol esters was HPLC with isocratic elution mode using octadecylsilyl packing in the reverse-phase mode, and, less frequently, aminopropylsilyl packing in the normal phase mode. Determination of beta carotene in medicinal products is most often performed using spectrophotometry. 

1978 ◽  
Vol 24 (11) ◽  
pp. 1920-1923 ◽  
Author(s):  
M G DeRuyter ◽  
A P De Leenheer

Abstract We propose a single-run liquid-chromatographic determination, with ultraviolet detection at 330 nm, for serum retinol and retinyl esters. The vitamin A derivatives are extracted according to the Bligh-Dyer procedure. With 200 microliter or serum, the lower detection limit is 50 microgram/liter for retinol and about 100 microgram/liter for retinyl esters. Within-run precision (CV) was 2.3% for retinol, 4.3% for retinyl palmitate. Day-to-day percision (CV, n = 20) for retinol was 4.9% during a month. The method can be used for the assessment of vitamin A absorption tests and for the determination of serum retinol (normal, subnormal, and above-normal concentrations). Serum retinyl esters can only be measured in conditions where concentrations exceed 100 microgram/liter.


2002 ◽  
Vol 72 (4) ◽  
pp. 199-203 ◽  
Author(s):  
Márcia Zanutto ◽  
Alceu Jordão Júnior ◽  
Mônica Meirelles ◽  
Rosa Fávaro ◽  
Hélio Vannucchi

The effect of citric pectin on the bioavailability of synthetic beta-carotene was studied. Thirty Wistar rats were used, ten animals were sacrificed at the beginning of the experiment and remaining animals were divided into two groups and received the following diets for 30 days: control group (CG) – 24 mg beta-carotene/g diet + 0% citric pectin; experimental group (EG) – 24 mugbeta-carotene/g diet + 7% citric pectin. Plasma and liver beta-carotene, vitamin A, and retinyl palmitate concentrations were determined by high-performance liquid chromatography (HPLC). Plasma retinol concentration was 1.42 ± 0.36 mumol/L for CG and 1.10 ± 0.24 mumol/L for EG (p = 0.1), and plasma beta-carotene concentration was 0.20 ± 2.51 mumol/L for CG and 0.07 ± 0.04 µumol/L for EG (p = 0.01). Only traces of retinyl palmitate were detected in CG and none in EG. Retinol did not differ significantly between groups CG and EG, while a significantly higher beta-carotene concentration was observed for CG. Liver concentrations of retinol (CG: 4.90 ± 2.51 µug/g; EG: 2.68 ± 1.12 µug/g), beta-carotene (CG: 0.98 ± 0.28 µug/g; EG: 0.11 ± 0.06 µug/g), and retinyl palmitate (CG: 95.47 ± 45.13 µug/g, EG: 37.01 ± 17.20 µug/g) differed significantly between groups (p < 0.05), with a lower concentration being observed for EG. We conclude that 7% citric pectin in the rat diet decreases the bioavailability of synthetic beta-carotene, reducing the liver reserves of vitamin A and beta-carotene.


1999 ◽  
Vol 47 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Annamária Kerti ◽  
L. Bárdos

The present study was designed to investigate the effect of a one-month feeding of retinyl acetate (RA) on the retinol (ROL), retinyl palmitate (RP) and (-carotene (BC) levels in the blood, testicles and ovarian follicles of adult Japanese quails. The basal diet (containing vitamin A at 10 × 103IU/kg) was supplemented with 100 ×, 500 × and 1000 × 103IU/kg RA in Groups I, II and III in both sexes. Plasma vitamin A levels rose in all groups. The elevations were caused basically by the RP fraction. The ROL concentration increased only slightly, indicating saturation of the blood binding/transport system. Plasma BC was depressed in both sexes. RA feeding resulted in high RP concentration in the genital organs (testicles and ovarian follicles), indicating subclinical hypervitaminosis, while the BC content of genital organs decreased considerably. The retinoid and BC concentration of ovarian follicles (F1-F5) was in the same range, indicating continuous retinoid and carotene transport during the fast maturation period. Retinoid content of the genital organs was higher in layers than in roosters. BC deposition was decreased both in the testicles and in the follicles, indicating a competition between RP and BC for the storage capacity of organs.


2016 ◽  
Vol 99 (1) ◽  
pp. 223-241 ◽  
Author(s):  
Adrienne McMahon ◽  
S Christiansen ◽  
F-F Chee ◽  
A Chua ◽  
H Braddock ◽  
...  

Abstract The main objective of the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) project is to establish international consensus methods for infant formula and adult nutritionals, which will benefit intermarket supply and dispute resolution. A collaborative study was conducted on AOAC First Action Method 2012.10 Simultaneous Determination of 13-cis and All-trans Vitamin A Palmitate (Retinyl Palmitate), Vitamin A Acetate (Retinyl Acetate), and Total Vitamin E (α-Tocopherol and D-α-tocopherol acetate) in Infant Formula and Adult Nutritionals by Normal-Phase HPLC. Fifteen laboratories from 11 countries participated in an interlaboratory study to determine 13-cis and all-trans vitamin A palmitate (retinyl palmitate), vitamin A acetate (retinyl acetate), and total vitamin E (α-tocopherol and D-α-tocopherol acetate) in infant formula and adult nutritionals by normal-phase HPLC and all laboratories returned valid data. Eighteen test portions of nine blind duplicates of a variety of infant formula and adult nutritional products were used in the study. The matrixes included milk-based and soy-based hydrolyzed protein as well as a low fat product. Each of the samples was prepared fresh and analyzed in singlicate. As the number of samples exceeded the recommended number to be prepared in a single day, analysis took place over 2 days running 12 samples on day one and 10 samples on day two. The reference standard stock was prepared once and the six-point curve diluted freshly on each day. Results obtained from all 15 laboratories are reported. The RSDR for total vitamin A (palmitate or acetate) ranged from 6.51 to 22.61% and HorRat values ranged from 0.33 to 1.25. The RSDR for total vitamin E (as tocopherol equivalents) ranged from 3.84 to 10.78% and HorRat values ranged from 0.27 to 1.04. Except for an adult low fat matrix which generated reproducibility RSD &gt;40% for some isomers, most SPIFAN matrixes gave results within the acceptance criteria of &lt;16% RSD as stated in the respective Standard Method Performance Requirements.


1996 ◽  
Vol 270 (3) ◽  
pp. L475-L482 ◽  
Author(s):  
N. C. Paquette ◽  
L. Y. Zhang ◽  
W. A. Ellis ◽  
A. L. Scott ◽  
S. R. Kleeberger

The present study determined the effects of vitamin A (vA) deficiency on the responses to ozone (O3) challenges in two inbred strains of mice that are differentially susceptible to O3-induced lung inflammation. Susceptible C57BL/6J (B6) and resistant C3H/HeJ (C3) dams at 2 wk gestation were fed test diets containing either 0 or 10 micrograms retinol/g diet. In mice that were maintained on vA-sufficient (vA+) diet, lung and liver tissue concentrations of vA and retinyl palmitate (RP) were significantly (P<0.05) lower in the B6 strain compared with C3, as measured by high-performance liquid chromatography techniques. vA and RP levels were significantly (P<0.05) reduced in lung and liver tissues of 8-wk old B6 and C3 mice that were maintained on a vA deficient (vA-) diet. vA+ and vA- mice of both strains were exposed to air or 0.3 ppm O3/72 h, and lung injury was assessed by differential cell count and total protein concentration in bronchoalveolar lavage (BAL) returns. O3 exposure caused significantly (P<0.05) greater increases in inflammatory cells and a total protein in BAL returns of vA+ B6 mice than vA+ C3 mice. vA deficiency significantly (P<0.05) enhanced O3-induced increases in polymorphonuclear leukocytes in C3 mice and epithelial cells loss in both strains. Compared with vA+ mice, lung permeability was also significantly (P<0.05) enhanced in vA- mice of both strains exposed to O3. vA replacement partially reversed the O3-induced lung injury that was enhanced by vA- diet. Results indicate that vA may have an important role in the pathogenesis of O3-induced lung injury in differentially susceptible inbred strains of mice.


2008 ◽  
Vol 400-402 ◽  
pp. 137-143 ◽  
Author(s):  
Vinod Rajayogan ◽  
Obada Kayali

Determination of a realistic model for the estimation of autogenous shrinkage in plain cement mixtures has been an ongoing research among researchers in high performance concrete. While no standard test method exists for the determination of autogenous shrinkage, various researchers have designed different test methods for measurement of autogenous shrinkage. Current study involved the experimental determination of autogenous shrinkage using the test method developed by O.M.Jensen and co-workers, complimented with non-contact eddy current sensors. Measurements were conducted from as early as 1.5 hours from the time of casting. The samples were placed in a constant temperature chamber and the temperature of the sample was also monitored using a thermocouple. The study was carried out on plain cement mixtures at three water cement ratios of 0.25, 0.32 and 0.38. Measurements were also conducted on simple sealed prismatic samples but these measurements could only be collected after 24 hours of casting. The work is supplemented with CEMHYD3D simulations of the samples at similar water-cement ratios under sealed conditions so as to understand the development of the microstructure of the cement responsible for autogenous shrinkage. While experimental determination of internal relative humidity is quite difficult, data regarding chemical shrinkage, amount of water left and the development of the discontinuous capillary network from the simulations help to understand the determined experimental values of autogenous shrinkage. A detailed explanation on the causes of autogenous shrinkage and the basic mechanism responsible for it has been presented.


1993 ◽  
Vol 39 (11) ◽  
pp. 2229-2234 ◽  
Author(s):  
Z Zaman ◽  
P Fielden ◽  
P G Frost

Abstract A reversed-phase high-performance liquid-chromatographic method for the simultaneous determination of retinol, alpha-tocopherol, alpha-carotene, beta-carotene, cryptoxanthin, lutein/zeaxanthin, and lycopene is described. This method was applied to plasma measurements in healthy young and elderly subjects. The plasma, deproteinized with ethanol, is extracted twice with n-hexane. After evaporation, the residue is dissolved in 50 microL of tetrahydrofuran and made up to 200 microL with ethanol. Samples (50 microL) are injected onto a 250 x 4.6 mm column of 5-microns-particle Spherisorb ODS1 (Phase Separations) that had been equilibrated with solvent mixture A:B (90:10 by vol) [A = 100 mmol/L ammonium acetate in methanol: acetonitrile (80:20 by vol) and B = 100 mmol/L ammonium acetate in water] at 2 mL/min. The analytes are eluted by running a 12-min linear gradient to 100% A; solvent A is then maintained for 10 min. Intrabatch CVs were 2.3%, 3.3%, 2.8%, 3.6%, 3.6%, and 3.0% for retinol, alpha-tocopherol, lutein/zeaxanthin, cryptoxanthin, lycopene, and beta-carotene, respectively. The corresponding interbatch CVs were 4.9%, 5.8%, 12.3%, 6.5%, 8.0%, and 3.4%.


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