Analysis of Fat-Soluble Vitamins. XXVI. High Performance Liquid Chromatographic Determination of Vitamin D in Fortified Milk and Milkpowder

1982 ◽  
Vol 65 (5) ◽  
pp. 1225-1227
Author(s):  
Ben Borsje ◽  
Ellen J De Vries ◽  
Jakob Zeeman ◽  
Frits J Mulder
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Fortified Milk ◽  
Liquid Chromatographic Determination ◽  
Fat Soluble Vitamins ◽  
Liquid Chromatographic

Abstract Vitamin D is determined by high performance liquid chromatography (HPLC) in samples containing other fat-soluble vitamins. The vitamin D in the unsaponifiable residue is extracted and separated from interferences by straight phase chromatography, and the fraction corresponding to vitamin D3 is collected and quantitated using the AOAC official final action HPLC method for vitamin D3. Analysis of a synthetic mixture gave reasonable recoveries. The method measures potential vitamin D3 content in milkpowder samples containing 2IU vitamin D/g in the presence of all known vitamin D3 isomers, vitamin A, and vitamin E.

Analysis of Fat-Soluble Vitamins. XXIV. High Performance Liquid Chromatographic Determination of Vitamin D in Vitamin D Resin Containing Powders: Collaborative Study1

1981 ◽  
Vol 64 (1) ◽  
pp. 58-60
Author(s):  
Frits J Mulder ◽  
Ellen J De Vries ◽  
Ben Borsje ◽  
◽  
L Ameika ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Dry Powders ◽  
Liquid Chromatographic Determination ◽  
The Difference ◽  
Fat Soluble Vitamins ◽  
Liquid Chromatographic

Abstract Further study of vitamin D methodology solved the discrepancy between the AOAC chemical method, 43.068-43.078, and the HPLC assay for vitamin D3 in resin containing dry powders. The discrepancy is caused by the difference in solubility of the vitamin D3 resin in benzene and in pentane. The method has been modified accordingly, and has been adopted official first action for vitamin D3 resins and vitamin D3 resin containing powders and aqueous dispersions.

Analysis of Fat-Soluble Vitamins. XXV. High Performance Liquid Chromatographic Determination of Vitamin D in Multivitamin Preparations: Collaborative Study1

1981 ◽  
Vol 64 (1) ◽  
pp. 61-70
Author(s):  
Ellen J De Vries ◽  
Frits J Mulder ◽  
Ben Borsje ◽  
◽  
L Ameika ◽  
...  
Keyword(s):  
Vitamin D ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Phase System ◽  
Single Column ◽  
Liquid Chromatographic Determination ◽  
Fat Soluble Vitamins ◽  
Liquid Chromatographic

Abstract The HPLC method for determining vitamin D in multivitamin preparations was studied collaboratively. Samples were distributed to 43 laboratories in 10 countries. Twenty-four laboratories gave their results. The method specifies a reverse phase system for the cleanup and a straight phase system for the determination. Difficulties arise when laboratories are equipped with HPLC apparatus with a single column. Laboratories experienced in vitamin D analysis reported good results, even if they were equipped with a single column HPLC apparatus. Eleven of the 24 laboratories reported satisfactory results. For this rather complicated method, the coefficient of variation for a single assay is acceptable. The method has been adopted official first action as an alternative procedure to the chemical method for determining vitamin D in multivitamins.

Analysis of Fat-Soluble Vitamins. XXVII. High Performance Liquid Chromatographic arid Gas-Liquid Chromatographic Determination of Vitamin D in Fortified Milk and Milkpowder: Collaborative Study

1982 ◽  
Vol 65 (5) ◽  
pp. 1228-1234
Author(s):  
Ellen J De Vries ◽  
Ben Borsje ◽  
◽  
L Ameika ◽  
N T Baillies ◽  
...  
Keyword(s):  
Vitamin D ◽  
High Performance ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Fortified Milk ◽  
Whole Milk ◽  
Fat Soluble Vitamins ◽  
Liquid Chromatographic

Abstract A collaborative study of the high performance liquid chromatographic (HPLC) method for vitamin D in fortified milkpowder (skimmed and whole milk) and a milkpowder preparation was carried out on 182 samples distributed to 26 laboratories. Thirteen laboratories submitted results. The level of vitamin D was 2-7IU vitamin D3/g milkpowder. All samples also contained vitamin A. Three laboratories were excluded from the statistical evaluation because of incomplete results or deviation from the analytical procedure. Other laboratories reported acceptable results. At the same time, 63 samples were distributed to 9 laboratories which used a gas-liquid chromatographic method for determining vitamin D in milkpowder. Only one laboratory reported results. The HPLC method has been adopted official first action.

Analysis of Fat-Soluble Vitamins. XXII. High Performance Liquid Chromatographic Determination of Vitamin D in Concentrates. Collaborative Study1

1979 ◽  
Vol 62 (5) ◽  
pp. 1031-1040
Author(s):  
Frits J Mulder ◽  
Ellen J De Vries ◽  
Ben Borsje
Keyword(s):  
Vitamin D ◽  
High Performance ◽  
Chemical Method ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
De Vries ◽  
Fat Soluble Vitamins ◽  
Liquid Chromatographic

Abstract A collaborative study was carried out which compared the official chemical method (43.B14- 43.B24), the HPLC method according to Hofsass et al. including maleic anhydride treatment, and the HLPC procedure according to De Vries et al. for vitamin D concentrates. A total of 396 samples were distributed to 33 collaborators for analysis. Five laboratories performed both the chemical and the HPLC methods. Five laboratories performed the Hofsass method and 16 laboratories performed the De Vries method. The results for the chemical method agreed with the theoretical values for the samples, and the standard deviation was comparable to that obtained in previous AOAC collaborative studies. Collaborative results for the Hofsass method were low. In addition, incorrect use of a fixed conversion factor (1/0.586) and necessity of a double chromatographic system on a non-treated and a treated vitamin D sample reduce the effectiveness of the method. There were no adverse reactions to the De Vries HPLC method. It is recommended that the method be adopted official first action as an alternative procedure for determining vitamin D in concentrates, excluding powders containing irradiated 7-dehydrocholesterol.

High Performance Liquid Chromatographic Determination of Primidone in Tablets

1982 ◽  
Vol 65 (5) ◽  
pp. 1063-1065
Author(s):  
Stanley E Roberts
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Average Recovery ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high performance liquid chromatographic (HPLC) method is described for the quantitative determination of primidone in tablets. A ground tablet sample is diluted directly in the mobile phase, at a concentration of about 1 mg/mL of primidone, mixed and deaerated, and filtered. The resulting solution is then quantitated by HPLC. The average spike recoveries for the 50 mg and 250 mg tablets were 101.2% and 99.0%, respectively. The average recovery for an authentic mixture formulated at the 250 mg level was 100.1% with a relative standard deviation of 0.45%.

Analysis of Fat-Soluble Vitamins. XXIII. High Performance Liquid Chromatographic Assay for Vitamin D in Vitamin D3 and Multivitamin Preparations1

1979 ◽  
Vol 62 (6) ◽  
pp. 1285-1291
Author(s):  
Ellen J De Vries ◽  
Jakob Zeeman ◽  
Robert J E Esser ◽  
Ben Borsje ◽  
Frits J Mulder
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Coefficient Of Variation ◽  
High Performance ◽  
Conversion Factor ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
External Standard ◽  
Fat Soluble Vitamins ◽  
Liquid Chromatographic

Abstract Vitamin D is determined in preparations containing other fat-soluble vitamins by high performance liquid chromatography (HPLC). The unsaponifiable residue is extracted and separated from interferences by reverse phase chromatography; the fraction corresponding to vitamin D3 is collected and quantitated using normal phase chromatography (amylalcohol-n-hexane as mobile phase) by measuring the vitamin D3 and previtamin D3 peaks at 254 nm. Previtamin D3 content is calculated as vitamin D3 with a conversion factor (determined on the equipment used). Application of the method to vitamin AD3 mixtures in oils gives 98-102% recovery. The reproducibility, using an external standard, is 2-3%, calculated as the coefficient of variation; with an internal standard, the coefficient of variation is 1-1.5%. The method measures potential vitamin D3 content in preparations containing ≽ 200 IU/g in the presence of all known vitamin D3 isomers, vitamin A, and vitamin E.

Simultaneous liquid-chromatographic determination of prednisone and prednisolone in plasma.

1988 ◽  
Vol 34 (9) ◽  
pp. 1897-1899 ◽  
Author(s):  
M H Cheng ◽  
W Y Huang ◽  
A I Lipsey
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract This high-performance liquid-chromatographic (HPLC) method for simultaneous determination of prednisone and its metabolite, prednisolone, in plasma is a modification of the method of Frey et al. (Clin Chem 1979;25:1944-7). Heparinized plasma (1.0 mL) with 0.1 mL of internal standard solution (11-deoxy-17-hydroxycorticosterone, 2 mg/L) is extracted with 7.0 mL of dichloromethane, then washed sequentially with 0.1 mol/L HCl, 0.1 mol/L NaOH, and deionized water, 2.0 mL each. The extract is evaporated and the residue reconstituted with 75 microL of mobile phase, methanol/H2O (40/60 by vol). Thirty microliters of this is injected onto a reversed-phase C6 column, which is eluted at 1.4 mL/min. Analytical recoveries of prednisone and prednisolone were 94-98% and 102-106%, respectively. Day-to-day precision (CV) was 3.8% for prednisone, 6.1% for prednisolone. We encountered no interference from the 21 other steroids and 25 drugs tested. This method is simple, accurate, and precise.

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