scholarly journals Determination of Ubidecarenone (Coenzyme Q10, Ubiquinol-10) in Raw Materials and Dietary Supplements by High-Performance Liquid Chromatography with Ultraviolet Detection: Single-Laboratory Validation

2007 ◽  
Vol 90 (5) ◽  
pp. 1227-1236 ◽  
Author(s):  
Debra Orozco ◽  
Jules Skamarack ◽  
Kelly Reins ◽  
Barry Titlow ◽  
Steve Lunetta ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Dietary Supplements ◽  
Coenzyme Q10 ◽  
High Performance ◽  
Raw Materials ◽  
Biologically Active ◽  
Ultraviolet Detection ◽  
Relative Standard ◽  
Single Laboratory

Abstract A method based on high-performance liquid chromatography with ultraviolet detection has been developed to quantify ubidecarenone [coenzyme Q10 (CoQ10)] in raw materials and dietary supplements. Single-laboratory validation has been performed on the method to determine repeatability, accuracy, selectivity, limits of detection and quantification (LOQ), ruggedness, and linearity for CoQ10. As CoQ10 can exist as the biologically active reduced form, the application of an oxidizing agent, ferric chloride, drives the equilibrium mechanics to the fully oxidized state and allows for exact quantification of total CoQ10 in the sample. This method was found to be fit and linear for the testing of materials containing CoQ10 in the range of 501000 mg/g. Repeatability precision for CoQ10 was between 2.15 and 5.00 relative standard deviation. Observed recovery of CoQ10 was found to be between 93.8 and 100.9. LOQ was found to be 9 g/mL. Further, limited studies showed that some adulterants and degraded material could be satisfactorily separated from CoQ10 and identified.

scholarly journals Single Laboratory Validation of a Method for Determination of Glucosamine in RawMaterials and Dietary Supplements Containing Glucosamine Sulfate and/or Glucosamine Hydrochloride by High-Performance Liquid Chromatography with FMOC-Su Derivatization

2004 ◽  
Vol 87 (5) ◽  
pp. 1083-1092 ◽  
Author(s):  
Joseph ZiQi Zhou ◽  
Ted Waszkuc ◽  
Felicia Mohammed
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Dietary Supplements ◽  
High Performance ◽  
Raw Materials ◽  
Glucosamine Sulfate ◽  
Glucosamine Hydrochloride ◽  
Relative Standard ◽  
Single Laboratory

Abstract Single laboratory validation of a method for determination of glucosamine in raw materials and dietary supplements containing glucosamine sulfate and/or glucosamine hydrochloride by with high-performance liquid chromatography FMOC-Su derivatization. Tests with 2 blank matrixes containing SAMe, vitamin C, citric acid, chondroitin sulfates, methylsulfonylmethane, lemon juice concentrate, and other potential interferents showed the method to be selective and specific. Eight calibration curves prepared over 7 working days indicated excellent reproducibility with the linear range at least over 2.0–150 μg/mL, and determination coefficients >0.9999. Average spike recovery from the blank matrix (n = 8 over 2 days) was 93.5, 99.4, and 100.4% at respective spike levels of 15, 100, and 150%, and from the sample matrix containing glucosamine (n = 3) was 99.9 and 102.8% at respective levels of 10 and 40%, with relative standard deviations <0.9%. The method was also applied to 12 various glucosamine finished products and raw materials. The stability tests confirmed that glucosamine–FMOC-Su derivative once formed is stable at room temperature for at least 5 days. Limit of quantitation was 1 μg/mL and limit of detection was 0.3 μg/mL. The method is ready to proceed for the collaborative study.

scholarly journals Determination of Chondroitin Sulfate Content in Raw Materials and Dietary Supplements by High-Performance Liquid Chromatography with Ultraviolet Detection After Enzymatic Hydrolysis: Single-Laboratory Validation

2007 ◽  
Vol 90 (3) ◽  
pp. 659-669 ◽  
Author(s):  
David Ji ◽  
Mark Roman ◽  
Joseph Zhou ◽  
Jana Hildreth
Keyword(s):  
Liquid Chromatography ◽  
Chondroitin Sulfate ◽  
Dietary Supplements ◽  
Limit Of Detection ◽  
Raw Materials ◽  
Negative Control ◽  
Sulfate Content ◽  
Ultraviolet Detection ◽  
Relative Standard ◽  
Single Laboratory

Abstract A method to quantify chondroitin sulfate in raw materials and dietary supplements at a range of about 5 to 100% (w/w) chondroitin sulfate has been developed and validated. The chondroitin sulfate is first selectively hydrolyzed by chondroitinase ACII enzyme to form un-, mono-, di-, and trisulfated unsaturated disaccharides; the resulting disaccharides are then quantified by ion-pairing liquid chromatography with ultraviolet detection. The amounts of the individual disaccharides are summed to yield the total amount of chondroitin sulfate in the material. Single-laboratory validation has been performed to determine the repeatability, accuracy, selectivity, limit of detection, limit of quantification, ruggedness, and linearity of the method. Repeatability precision for total chondroitin sulfate content was between 1.60 and 4.72% relative standard deviation, with HorRat values between 0.79 and 2.25. Chondroitin sulfate recovery from raw material negative control was between 101 and 102%, and recovery from finished product negative control was between 105 and 106%.

scholarly journals Determination of Aristolochic Acid in Botanicals and Dietary Supplements by Liquid Chromatography with Ultraviolet Detection and by Liquid Chromatography/Mass Spectrometry: Single Laboratory Validation Confirmation

2006 ◽  
Vol 89 (4) ◽  
pp. 942-959 ◽  
Author(s):  
William A Trujillo ◽  
Wendy R Sorenson ◽  
Paul La Luzerne ◽  
John W Austad ◽  
Darryl Sullivan
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Dietary Supplements ◽  
Aristolochic Acid ◽  
Automation System ◽  
Ultraviolet Detection ◽  
Relative Standard ◽  
Single Laboratory ◽  
Aristolochic Acid I

Abstract The presence of aristolochic acid in some dietary supplements is a concern to regulators and consumers. A method has been developed, by initially using a reference method as a guide, during single laboratory validation (SLV) for the determination of aristolochic acid I, also known as aristolochic acid A, in botanical species and dietary supplements at concentrations of approximately 2 to 32 μg/g. Higher levels were determined by dilution to fit the standard curve. Through the SLV, the method was optimized for quantification by liquid chromatography with ultraviolet detection (LC-UV) and LC/mass spectrometry (MS) confirmation. The test samples were extracted with organic solvent and water, then injected on a reverse phase LC column. Quantification was achieved with linear regression using a laboratory automation system. The SLV study included systematically optimizing the LC-UV method with regard to test sample size, fine grinding of solids, and solvent extraction efficiency. These parameters were varied in increments (and in separate optimization studies), in order to ensure that each parameter was individually studied; the test results include corresponding tables of parameter variations. In addition, the chromatographic conditions were optimized with respect to injection volume and detection wavelength. Precision studies produced overall relative standard deviation values from 2.44 up to 8.26% for aristolochic acid I. Mean recoveries were between 100 and 103% at the 2 μg/g level, between 102 and 103% at the 10 μg/g level, and 104% at the 30 μg/g level.

scholarly journals Determination of Coenzyme Q10 in Over-the-Counter Dietary Supplements by High-Performance Liquid Chromatography with Coulometric Detection

2006 ◽  
Vol 89 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Peter H Tang
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Dietary Supplements ◽  
Coenzyme Q10 ◽  
High Performance ◽  
Limit Of Detection ◽  
Detector Response ◽  
Over The Counter ◽  
Coulometric Detection

Abstract A rapid and sensitive method is described for the determination of coenzyme Q10 (Q10) in over-the-counter dietary supplements by automated high-performance liquid chromatography (HPLC) with coulometric detection. Sample solutions of powder-filled capsules, oil-based softgels, and tablets were prepared by serial dilution with 1-propanol. After dilution, a known volume of sample solution containing Q10 and the internal standard, coenzyme Q9 (Q9), was directly injected into the HPLC system. Most of electrochemically active compounds in the injection were oxidized at the precolumn conditioning cell and postcolumn guard cell. Q9 and Q10 were monitored at an analytical cell that contained 2 coulometric electrodes, where Q9 and Q10 were reduced to the corresponding ubiquinol-9 and -10 and then oxidized to produce currents. This method produced a linear detector response for peak height measurements over the concentration range of 0.058 g/mL (r > 0.999). The lower limit of detection was 5 ng/mL (signal-to-noise ratio, 3). The mean recovery was 98.9 0.6%; coefficients of variation for intra- and interday precisions were 1.84.0%. The proposed method was successfully applied to the determination of Q10 in marketed products.

scholarly journals Method for the Determination of β-Carotene in Supplements and Raw Materials by Reversed-Phase Liquid Chromatography: Single Laboratory Validation

2004 ◽  
Vol 87 (5) ◽  
pp. 1070-1082 ◽  
Author(s):  
Joseph Schierle ◽  
Bernd Pietsch ◽  
Alan Ceresa ◽  
Christian Fizet ◽  
Edward H Waysek
Keyword(s):  
Liquid Chromatography ◽  
Dietary Supplements ◽  
Raw Materials ◽  
Collaborative Study ◽  
Reversed Phase ◽  
Raw Material ◽  
Relative Standard ◽  
Single Laboratory ◽  
Β Carotene

Abstract A single laboratory validation (SLV) study was conducted for a liquid chromatography (LC) method for the determination of total and all-trans-β-carotene in a variety of dietary supplements, including multivitamin tablets, softgels, capsules, and beadlet raw materials. Extraction variants were developed for the different types of supplements tested based upon the supplement type and level of β-carotene. Water dispersible formulations such as powders, emulsions, tablets, and capsules were enzymatically digested with protease and extracted with dichloromethane–ethanol. Oily suspensions were directly dissolved in dichloromethane–ethanol. After appropriate dilution or concentration, the extracts were chromatographed by using either a reversed-phase C18 column or, in products containing high amounts of α-carotene, a reversed-phase C30 column. The LC systems provided linear responses in the range of 0.1–50 μg β-carotene/mL. The main geometrical isomers of β-carotene (all-trans, 9-cis, 13-cis, and 15-cis) were well separated from each other and from other carotenoids such as α-carotene, cryptoxanthin, lutein, lycopene, and zeaxanthin. Duplicate determinations of total β-carotene performed by 2 technicians in 8 different test materials on 5 different days resulted in relative standard deviations of 1.2–4.4%. Recoveries determined for supplements and beadlet raw material spiked with β-carotene levels of 10 μg to 100 mg/test portion and 0.2–40%, respectively, ranged from 97.5 to 102.1%. On the basis of the accuracy, precision, and recovery results from the SLV study, the method is suggested for a collaborative study on the determination of total and all-trans-β-carotene in dietary supplements.

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