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 Determination of Campesterol, Stigmasterol, and beta-Sitosterol in Saw Palmetto RawMaterials and Dietary Supplements by Gas Chromatography: Single-Laboratory Validation

2006 ◽  
Vol 89 (1) ◽  
pp. 22-34 ◽  
Author(s):  
Wendy R Sorenson ◽  
Darryl Sullivan
Keyword(s):  
Gas Chromatography ◽  
Dietary Supplements ◽  
Task Force ◽  
Raw Materials ◽  
Potassium Hydroxide Solution ◽  
Correlation Coefficients ◽  
Official Method ◽  
Unsaponifiable Fraction ◽  
Saw Palmetto ◽  
Relative Standard

Abstract In conjunction with an AOAC Presidential Task Force on Dietary Supplements, a method was validated for measurement of 3 plant sterols (phytosterols) in saw palmetto raw materials, extracts, and dietary supplements. AOAC Official Method 994.10, Cholesterol in Foods, was modified for purposes of this validation. Test samples were saponified at high temperature with ethanolic potassium hydroxide 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 a hydrogen flame ionization detector. The presence of the phytosterols was detected at concentrations greater than or equal to 1.00 mg100 g based on 23 g of sample. The standard curve range for this assay was 0.00250 to 0.200 mgmL. The calibration curves for all phytosterols had correlation coefficients greater than or equal to 0.995. Precision studies produced relative standard deviation values of 1.52 to 7.27% for campesterol, 1.62 to 6.48% for stigmasterol, and 1.39 to 10.5% for beta-sitosterol. Recoveries for samples fortified at 100% of the inherent values averaged 98.5 to 105% for campesterol, 95.0 to 108% for stigmasterol, and 85.0 to 103% for beta-sitosterol.

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.

scholarly journals Determination of Hydrastine and Berberine in Goldenseal Raw Materials, Extracts, and Dietary Supplements by High-Performance Liquid Chromatography with UV: Collaborative Study

2008 ◽  
Vol 91 (4) ◽  
pp. 694-701 ◽  
Author(s):  
Paula N Brown ◽  
Mark C Roman ◽  
C Chang ◽  
C Jin ◽  
R Kuriyedath ◽  
...  
Keyword(s):  
Dietary Supplements ◽  
High Performance ◽  
Raw Materials ◽  
Collaborative Study ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Uv Detection ◽  
Acetonitrile Solution ◽  
Relative Standard

Abstract A multilaboratory collaborative study was conducted on a high-performance liquid chromatographic (HPLC) method utilizing UV detection, previously validated using AOAC single-laboratory validation guidelines for determination of hydrastine and berberine in goldenseal (Hydrastis canadensis L.) raw materials, extracts, and dietary supplements at levels ranging from 0.4 to 6 (w/w). Nine collaborating laboratories determined the hydrastine and berberine content in 8 blind samples. Sample materials included powdered botanical raw materials, whole root material, and 4 finished product dietary supplements containing either goldenseal powdered root material or extract. The materials were extracted with an acidified water and acetonitrile solution. HPLC analyses of the extracts were performed on a C18 column using UV detection at 230 nm. Results for powdered root material and capsule products ranged from about 0.2 (w/w) for each alkaloid to about 4 (w/w) for each alkaloid. Liquid tincture results were approximately 40005000 g/mL for each alkaloid. Reproducibility relative standard deviations (RSDR) for hydrastine ranged from 2.68 to 6.65, with HorRat values ranging from 0.77 to 1.89. RSDR for berberine ranged from 5.66 to 7.68, with HorRat values ranging from 1.32 to 2.12. All finished products containing goldenseal extract yielded HorRat values <2.0. Based on these results, the method is recommended for Official First Action for determination of hydrastine and berberine in goldenseal raw materials and dietary supplement finished products containing powdered goldenseal and goldenseal extract.

scholarly journals Determination of Lycopene in Dietary Supplements and Raw Materials by High-Performance Liquid Chromatography: Collaborative Study

2010 ◽  
Vol 93 (2) ◽  
pp. 499-509 ◽  
Author(s):  
Edward H Waysek ◽  
Joseph Schierle ◽  
Andre Duesterloh ◽  
Jayant Deshpande ◽  
John Austad ◽  
...  
Keyword(s):  
Dietary Supplements ◽  
High Performance ◽  
Raw Materials ◽  
Collaborative Study ◽  
Negative Control ◽  
Study Results ◽  
Relative Standard ◽  
Lycopene Content ◽  
Standard Deviations

Abstract A collaborative study was conducted to evaluate the interlaboratory performance of an LC method for lycopene in dietary supplements and the raw materials commonly used in their manufacture. Twelve laboratories from six countries agreed to participate in the study. Results from 10 laboratories were received and are reported. Five dietary supplements, including both tablets and a softgel capsule with a lycopene content ranging from 25 g to 25 mg per unit, and three raw materials, including gelatin-based beadlets, vegetarian beadlets, and a suspension in oil ranging from 5 to 20 lycopene, were analyzed as blind duplicates. In addition to the commercial products, two positive controls and a negative control were included in the study. For the raw materials studied, the repeatability relative standard deviations (RSDr) ranged from 1.49 to 5.13 for total lycopene, and the reproducibility relative standard deviations (RSDR) ranged from 3.84 to 9.21 with HorRat values from 1.23 to 3.24. For finished products, the RSDr ranged from 1.31 to 4.62, RSDR from 4.28 to 10.5, and HorRat values from 0.79 to 2.07. Corresponding values for all-trans-lycopene were significantly higher. It is recommended that the method be considered for Official First Action for all-trans- and total lycopene in finished products and raw materials.

scholarly journals Determination of Coenzyme Q10 Content in Raw Materials and Dietary Supplements by High-Performance Liquid Chromatography-UV: Collaborative Study

2008 ◽  
Vol 91 (4) ◽  
pp. 702-708 ◽  
Author(s):  
Steven Lunetta ◽  
Mark Roman ◽  
A Chandrah ◽  
T Edamura ◽  
T Honda ◽  
...  
Keyword(s):  
Dietary Supplements ◽  
Coenzyme Q10 ◽  
High Performance ◽  
Raw Materials ◽  
Collaborative Study ◽  
Negative Control ◽  
Test Material ◽  
Relative Standard ◽  
Standard Deviations

Abstract An international collaborative study was conducted of a high-performance liquid chromatographic (HPLC)-UV method for the determination of coenzyme Q10 (CoQ10, ubidecarenone) in raw materials and dietary supplements. Ten collaborating laboratories determined the total CoQ10 content in 8 blind duplicate samples. Sample materials included CoQ10 raw material and 4 finished product dietary supplements representing softgels, hardshell gelatin capsules, and chewable wafers. In addition, collaborating laboratories received a negative control and negative control spiked with CoQ10 at low and high levels to determine recovery. Materials were extracted with an acetonitriletetrahydrofuranwater mixture. Ferric chloride was added to the test solutions to ensure all CoQ10 was in the oxidized form. The HPLC analyses were performed on a C18 column using UV detection at 275 nm. Repeatability relative standard deviations (RSDr) ranged from 0.94 to 5.05. Reproducibility relative standard deviations (RSDR) ranged from 3.08 to 17.1, with HorRat values ranging from 1.26 to 5.17. Recoveries ranged from 74.0 to 115. Based on these results, the method is recommended for Official First Action for determination of CoQ10 in raw materials and dietary supplement finished products containing CoQ10 at a concentration of >100 mg CoQ10/g test 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 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.

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 Simultaneous Determination of Chlorothalonil and Hexachlorobenzene in Technical and Formulated Materials by Capillary Gas Chromatography: Collaborative Study

2000 ◽  
Vol 83 (5) ◽  
pp. 1047-1052
Author(s):  
Linda D Vargyas ◽  
Gregory E Walls ◽  
William R Bramstedt ◽  
Gary L Eilrich ◽  
O Bennett ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Active Ingredient ◽  
Capillary Gas Chromatography ◽  
Collaborative Study ◽  
Data Systems ◽  
Capillary Gc ◽  
Relative Standard ◽  
Set Up

Abstract A collaborative study was conducted for the capillary gas chromatographic (GC) method for the simultaneous determination of the fungicide chlorothalonil (CTL) and the accompanying impurity, hexachlorobenzene (HCB), in technical and formulated materials. The method calls for the dissolution of technical and dry formulations of CTL and HCB from the aqueous flowable formulation. The 10 participating laboratories were asked to analyze the samples by adhering to the method as closely as their instrumentation and data systems allowed, and to note any deviations from the method. Collaborators were asked to prepare the standards and samples, set up the capillary GC systems, analyze the samples, and calculate the results. CTL produced reproducibility relative standard deviations (RSDR) of 0.4–2.5 (active ingredient concentrations ranged from approximately 52 to 98% by weight). HCB produced RSDR values of 5.2–22% (HCB concentrations were 0.02–0.04% by weight). The method was adopted First Action by AOAC INTERNATIONAL.

scholarly journals Determination of Glucosamine in Raw Materials and Dietary Supplements Containing Glucosamine Sulfate and/or Glucosamine Hydrochloride by High-Performance Liquid Chromatography with FMOC-Su Derivatization: Collaborative Study

2005 ◽  
Vol 88 (4) ◽  
pp. 1048-1058 ◽  
Author(s):  
Joseph Ziqi Zhou ◽  
Ted Waszkuc ◽  
Felicia Mohammed ◽  
M Blumhorst ◽  
R Buren ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Dietary Supplements ◽  
High Performance ◽  
Raw Materials ◽  
Collaborative Study ◽  
Test Results ◽  
Commercial Products ◽  
Glucosamine Hydrochloride

Abstract A collaborative study was conducted for determination of glucosamine in raw materials and dietary supplements containing glucosamine sulfate and/or glucosamine hydrochloride by high-performance liquid chromatography (HPLC) with N-(9-fluorenyl-methoxycarbonyloxy) succinimide (FMOC-Su) derivatization. Thirteen blind materials, one pair of which were duplicates, were tested by 12 collaborating laboratories. The test samples consisted of various commercial products, including tablets, capsules, drink mix, and liquids as well as raw materials, blanks, and those for spike recovery analyses. The tests with blank products and products spiked with glucosamine showed good specificity of the method. The average recoveries at spike levels of 100 and 150% of the declared amount were 99.0% with a relative standard deviation (RSD) of 2.1%, and 101% with an RSD of 2.3%, respectively. The test results between laboratories on each commercial product were reproducible with RSD values of no more than 4.0%, and the results were repeatable in the same laboratory with an average RSD of 0.7%. HorRat values ranged from 0.5 to 1.7 on both tests of spike recovery and reproducibility between laboratories on commercial products. The average determination coefficient of the calibration curves from the laboratories was 0.9995 with an RSD of 0.03%. All of the 12 collaborating laboratories succeeded in the study and none of their reported test results were outliers, partly indicating the robustness of the method. It is recommended that the method be accepted by AOAC INTERNATIONAL as Official First Action.

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