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.

Method for the Determination of Lycopene in Supplements and Raw Material by Reversed-Phase Liquid Chromatography: Single-Laboratory Validation

2008 ◽  
Vol 91 (6) ◽  
pp. 1284-1297 ◽  
Author(s):  
André Müller ◽  
Bernd Pietsch ◽  
Nicole Faccin ◽  
Joseph Schierle ◽  
Edward H Waysek
Keyword(s):  
Dietary Supplements ◽  
High Performance ◽  
Raw Materials ◽  
Reversed Phase ◽  
Raw Material ◽  
Intermediate Precision ◽  
Relative Standard ◽  
Product Forms ◽  
Single Laboratory

Abstract A single-laboratory validation study was conducted for a liquid chromatographic (LC) method for the determination of total and all-trans-lycopene in a variety of dietary supplements and raw materials. Gelatin-based and other water-dispersible beadlets, or tablets, capsules, and softgels containing such product forms, were digested with protease. Alginate formulations and the respective applications were treated with an alkaline sodium EDTA acetate buffer to release lycopene from the matrix. Lycopene and other carotenoids were extracted from the resulting aqueous suspensions with dichloromethane and ethanol. Oily product forms were directly dissolved in dichloromethane and ethanol. The extracts were chromatographed on an isocratic high-performance LC system using a C16 alkylamide modified silica column that provided satisfactory resolution of all-trans-lycopene from its predominant cis-isomers and separated the lycopene isomers from other carotenoids such as - and -carotene, cryptoxanthin, lutein, and zeaxanthin. The within-day precision relative standard deviation (RSD) for the determination of total lycopene ranged from 0.9 to 5.7 over concentration ranges of 50200 g/kg for raw materials and 0.324 g/kg for dietary supplements. The intermediate precision RSD (total RSD) ranged from 0.8 to 8.9. Recoveries obtained for beadlet and tablet material for the different extraction variants ranged from 95.0 to 102.1 at levels of 0.0220 g/kg for tablets and from 95.0 to 101.1 at levels of 1200 g/kg for beadlet material.

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 Clopidol Residues in Chicken Tissues by Liquid Chromatography: Collaborative Study

2003 ◽  
Vol 86 (4) ◽  
pp. 685-693 ◽  
Author(s):  
Guo-Fang Pang ◽  
Yan-Zhong Cao ◽  
Chun-Lin Fan ◽  
Jin-Jie Zhang ◽  
Xue-Min Li ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Solid Phase ◽  
Collaborative Study ◽  
Reversed Phase ◽  
Method Performance ◽  
Chicken Muscle ◽  
Relative Standard

Abstract Eighteen laboratories participated in a collaborative study on the determination of clopidol residues in chicken muscle tissues by liquid chromatography. Of these, results from 16 laboratories which rigorously followed the method were subjected to statistical analysis. The method performance was assessed by all participants using 14 samples of chicken muscle fortified at concentrations ranging from 0.1 to 5.0 mg/kg. In addition, 9 participants each reported results for 6 clopidol-incurred samples in chicken muscle. Test portions were extracted with acetonitrile, and the extracts were purified with alumina and anion exchange resin solid-phase extraction cartridges in sequence. Clopidol was separated by reversed-phase liquid chromatography and quantified at 270 nm. Average recoveries ranged from 81.8 to 85.4%, reproducibility relative standard deviation (RSDR) ranged from 11.9 to 22.6%, and repeatability relative standard deviation (RSDr) ranged from 9.9 to 15.1%. For clopidol-incurred samples at concentrations of 0.100–0.687 mg/kg, the mean determination value range was 0.099–0.659 mg/kg; RSDR was 12.6–19.8%, RSDr was 3.1–8.5%; and HORRAT values were 0.7–1.1. The accuracy and precision of the method are in conformity with the requirements specified by AOAC INTERNATIONAL. The method was adopted Official First Action in April 2003.

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 the Appetite Suppressant P57 in Hoodia gordonii Plant Extracts and Dietary Supplements by Liquid Chromatography/Electrospray Ionization Mass Spectrometry (LC-MSD-TOF) and LC-UV Methods

2006 ◽  
Vol 89 (3) ◽  
pp. 606-611 ◽  
Author(s):  
Bharathi Avula ◽  
Yan-Hong Wang ◽  
Rahul S Pawar ◽  
Yatin J Shukla ◽  
Brian Schaneberg ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Dietary Supplements ◽  
Reversed Phase ◽  
Ionization Mass ◽  
Active Constituent ◽  
Appetite Suppressant ◽  
Hoodia Gordonii ◽  
Relative Standard

Abstract Hoodia gordonii is traditionally used in South Africa for its appetite suppressant properties. P57AS3 (P57), an oxypregnane steroidal glycoside, is the only reported active constituent from this plant as an appetite suppressant. Effective quality control of these extracts or products requires rapid methods to determine P57 content. New methods of liquid chromatography/mass spectrometry (LC/MS) and LC-UV for analysis of P57 from H. gordonii have been developed. The quantitative determination of P57 was achieved with a Phenomenex Gemini (Torrance, CA) reversed-phase column using gradient mobile phase of water and acetonitrile, both containing 0.1% acetic acid. The method was validated for linearity, repeatability, and limits of detection and quantification. Good results were obtained in terms of repeatability (relative standard deviation <5.0%) and recovery (98.5103.5%). The developed methods were applied to the determination of P57 for H. gordonii plant samples, one related genus (Opuntia ficus-indica), and dietary supplements that claim to contain H. gordonii.

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 Campesterol, Stigmasterol, and Beta-Sitosterol in Saw Palmetto Raw Materials and Dietary Supplements by Gas Chromatography: Collaborative Study

2007 ◽  
Vol 90 (3) ◽  
pp. 670-678 ◽  
Author(s):  
Wendy R Sorenson ◽  
Darryl Sullivan ◽  
S Baugh ◽  
M Collison ◽  
R Das ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Dietary Supplements ◽  
Raw Materials ◽  
Collaborative Study ◽  
Unsaponifiable Fraction ◽  
Saw Palmetto ◽  
Relative Standard ◽  
Sample Test ◽  
Hydrogen Flame

Abstract An interlaboratory study was conducted to evaluate a method for the determination of campesterol, stigmasterol, and beta-sitosterol in saw palmetto raw materials and dietary supplements at levels >1.00 mg/100 g based on a 23 g sample. Test samples were saponified at high temperature with ethanolic KOH solution. The unsaponifiable fraction containing phytosterols (campesterol, stigmasterol, and beta-sitosterol) was extracted with toluene. Phytosterols were derivatized to trimethylsilyl ethers and then quantified by gas chromatography with hydrogen flame ionization detection. Twelve blind duplicates, one of which was fortified, were successfully analyzed by 10 collaborators. Recoveries were obtained for the sample that was fortified. The results were 99.8, 111, and 111% for campesterol, stigmasterol, and beta-sitosterol, respectively. For repeatability, the relative standard deviation (RSDr) ranged from 3.93 to 17.3% for campesterol, 3.56 to 22.7% for stigmasterol, and 3.70 to 43.9% for beta-sitosterol. For reproducibility, the RSDR ranged from 7.97 to 22.6%, 0 to 26.7%, and 5.27 to 43.9% for campesterol, stigmasterol, and beta-sitosterol, respectively. Overall, the Study Director approved 5 materials with acceptable HorRat values for campesterol, stigmasterol, and beta-sitosterol ranging from 1.02 to 2.16.

scholarly journals Simultaneous Determination of Vitamin A and β-Carotene in Dietary Supplements by Liquid Chromatography

2002 ◽  
Vol 85 (5) ◽  
pp. 1127-1135 ◽  
Author(s):  
P Ramnathan Sundaresan
Keyword(s):  
Liquid Chromatography ◽  
Solvent Extraction ◽  
Vitamin A ◽  
Dietary Supplements ◽  
Simultaneous Determination ◽  
Methylene Chloride ◽  
Reversed Phase ◽  
Phase Method ◽  
Β Carotene

Abstract Several liquid chromatography (LC) methods for analysis of vitamin A in oods and feeds have been previously reported but only a few have been applied in non-food matrixes. A validated LC method is needed for determination of vitamin A and β-carotene in the various matrixes presented by dietary supplements. The performance of a reversedphase method with methanol–isopropanol gradient elution was evaluated with standard retinyl derivatives and β-carotene. The reversed-phase method is capable of separating retinol from other derivatives such as retinyl acetate, retinyl palmitate, and β-carotene. Two types of extraction were used to extract the analytes from the dietary supplements: a hexane–methylene chloride extraction for soft-gel capsules containing β-carotene, and a direct solvent extraction for dietary supplements in tablet form. The direct solvent extraction consisted of treatment with ethanol and methylene chloride following addition of hot water (55°C). Results with the reversed-phase method for vitamin A and β-carotene in the products examined ( n = 8) indicated excellent method performance. The main form of vitamin A or β-carotene in dietary supplements was the all trans isomer. The reversed- phase method avoids saponification and is rapid, accurate, precise, and suitable for simultaneous determination of retinyl derivatives and β-carotene in dietary supplements.

scholarly journals Determination of Aconitum Alkaloids in Dietary Supplements and Raw Botanical Materials by Liquid Chromatography/UV Detection with Confirmation by Liquid Chromatography/Tandem Mass Spectrometry: Collaborative Study

2009 ◽  
Vol 92 (1) ◽  
pp. 111-118 ◽  
Author(s):  
Siu-Kay Wong ◽  
C T Che ◽  
H-Z Guo ◽  
S Ji ◽  
J-H Kim ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Dietary Supplements ◽  
Collaborative Study ◽  
Uv Detection ◽  
Tandem Mass ◽  
Aconitum Alkaloids ◽  
Relative Standard

Abstract An interlaboratory study was conducted to evaluate a method for the determination of 3 Aconitum alkaloids, viz., aconitine, mesaconitine, and hypaconitine, in raw botanical material and dietary supplements. The alkaloids were extracted with diethyl ether in the presence of ammonia. After cleanup by solid-phase extraction to remove matrix interferences, the alkaloids were determined by reversed-phase liquid chromatography (LC)/UV detection at 235 nm with confirmation by LC/tandem mass spectrometry (MS/MS). A total of 14 blind duplicates were successfully analyzed by 12 collaborators. For repeatability, the relative standard deviation (RSDr) values ranged from 1.9 to 16.7, and for reproducibility, the RSDR values ranged from 6.5 to 33. The HorRat values were all <2 with only one exception at 2.3. All collaborating laboratories had calibration curves with correlation coefficients of >0.998. In addition, 6 collaborators performed the confirmation and were able to verify the identities of the alkaloids by using LC/MS/MS.

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