Liquid Chromatographic Method for Determination of Explosives Residues in Soil: Collaborative Study

1990 ◽  
Vol 73 (4) ◽  
pp. 541-552 ◽  
Author(s):  
Christopher F Bauer ◽  
Stephan M Koza ◽  
Thomas F Jenkins
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Contaminated Soils ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Explosives Residues ◽  
Liquid Chromatographic

Abstract A collaborative study of a sonic extraction/liquid chromatographic method for determining nitroaromatic and nitramlne explosives In soil was conducted at 8 participating laboratories. Analytes HMX, RDX, TNB, DNB, tetryl, TNT, and 2,4-DNT were measured In duplicate for 4 field-contaminated soils and 4 spiked standard-matrix soils. Concentrations ranged from detection limits of about 1 μg/g to nearly 1000 μg/g. Results were evaluated with and without data Identified as outliers, which were often caused by electronic integrator miscalculation of chromatographic peak response. When outliers are excluded, method repeatability (within-laboratory relative standard deviation) for all analytes except tetryl Is less than 5% for spiked soils and less than 18% for fieldcontaminated soils. Relative standard deviation generally decreases as analyte concentration Increases. Reproducibility (between-laboratory relative standard deviation), except for tetryl and DNT, Is less than 7% for spiked soils and 26% for fleld-contamlnated soils. Thus, collaborators have nearly equivalent performance on spiked samples. For fleld-contamlnated soils, some additional Imprecision seems to result from the variability of extraction recoveries. Analyte recoveries from spiked soils are 95-97% for HMX, RDX, TNT, and DNT (similar to recoveries from aqueous samples); 92-93% for DNB and TNB; and 70% for tetryl. Poor results for tetryl (due to thermal degradation) are correctable If sonic bath temperatures are maintained near ambient. The method has been approved Interim official first action by AOAC.

scholarly journals Liquid Chromatographic Determination of Ampicillin Residues in Porcine Muscle Tissue by a Multipenicillin Analytical Method: European Collaborative Study

2002 ◽  
Vol 85 (4) ◽  
pp. 889-900 ◽  
Author(s):  
Eric Verdon ◽  
Pierric Couëdor ◽  
Pierre Maris ◽  
Michel Laurentie ◽  
P Batjoens ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Muscle Tissue ◽  
Phosphate Buffer ◽  
Collaborative Study ◽  
Porcine Muscle ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A collaborative study involving 14 laboratories was conducted to determine residues of ampicillin in porcine muscle tissue by using a liquid chromatographic method developed for multipenicillin analysis that can quantitate 8 penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, amoxicillin, nafcillin, oxacillin, cloxacillin, and dicloxacillin) at trace levels in muscle tissue. This method involves extraction of the penicillins with phosphate buffer, pH 9, followed cleanup and concentration on a C18 solid-phase extraction column and reaction with benzoic anhydride at 50°C and with 1,2,4-triazole and mercury(II) chloride solution, pH 9.0, at 65°C. The derivatized compounds are eluted isocratically on a C8 column with a mobile phase of acetonitrile and phosphate buffer (pH 6; 0.1M) containing sodium thiosulfate and the ion-pair reagent tetrabutylammonium hydrogen sulfate. The penicillins are detected by UV absorption at 325 nm. The limit of detection and the limit of determination (quantitation) of the method were calculated to be approximately 3–5 and 25 μg/kg, respectively, in accordance with the criteria of European Union (EU) Decision No. 93/256/EEC. In this first interlaboratory study, collaborators were instructed to monitor 4 different penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, and amoxicillin) by analyzing 8 blind samples of muscle tissue in triplicate. These samples were prepared from 2 materials containing different concentrations of incurred ampicillin (63.5 μg/kg for material No. 1 and 358.1 μg/kg for material No. 2) and 1 blank material. The repeatability relative standard deviation and the reproducibility relative standard deviation were 10.2 and 17.4%, respectively, for material No. 1 and 7.0 and 16.0%, respectively, for material No. 2. These results demonstrate that the method is suitable for the determination of ampicillin residues in muscle tissue at the EU maximum residue limit (50 μg/kg) and above. However, the identification of positives by this procedure may need additional confirmation by techniques with greater specificity, such as liquid chromatography combined with mass spectrometry, or tandem mass spectrometry. Investigations regarding the basis of interlaboratory testing studies will further demonstrate the suitability of multiresidue methodology for detecting and quantitating other compounds in the family of penicillin antibiotics.

Liquid Chromatographic Method for Determination of Glycerol in Wine and Grape Juice: Collaborative Study

1992 ◽  
Vol 75 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Arthur Caputi ◽  
Eric Christensen ◽  
Nancy Biedenweg ◽  
Susan Miller
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Grape Juice ◽  
External Standard Method ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
External Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract An Ion-exchange liquid chromatographic method for the determination of glycerol in wine, white grape juice, and pink grape juice was collaboratively studied by 8 laboratories. Eight wine types and 12 juice samples were provided to each collaborator. Using a strong cation column, blind duplicates and standards were analyzed by an external standard method. Separate statistical evaluations were run on wine, white grape juice, and pink grape juice data. The averages of the relative standard deviations for repeatability, excluding outlying results, were 1.25% for the wine samples, 7.32% for the white grape juice samples, and 8.63% for the pink grape juice samples. The averages of the relative standard deviations for reproducibility, excluding outlying results, were 2.79% for the wine samples, 16.97% for the white grape juice samples, and 19.10% for the pink grape juice samples. The method has been adopted first action by AOAC International.

Liquid Chromatographic Method for Multiresidue Determination of Benzimidazoles in Beef Liver and Muscle: Collaborative Study

1991 ◽  
Vol 74 (3) ◽  
pp. 487-493 ◽  
Author(s):  
Leon W Levan ◽  
Charlie J Barnes
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Study Data ◽  
Beef Liver ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Repeatability And Reproducibility ◽  
Multiresidue Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of thiabendazole, 5-hydroxythiabendazole, oxfendazole, mebendazole (MBZ), and fenbendazole (FBZ) In cattle liver and muscle was collaboratively studied in 7 laboratories In 1986. For blind fortified samples containing 800 ppb FBZ, average recovery and relative standard deviations for repeatability and reproducibility (RSDr and RSDR) based on results from 6 of the participating laboratories were 83%, 12.7%, and 14.0%, respectively. Recoveries of FBZ from incurred liver samples were more variable. Recoveries of MBZ from livers fortified at the 100 ppb level were encouraging; however, the drug levels were too low in the incurred samples used for MBZ studies. Except for FBZ and MBZ In liver, the study data were not satisfactory. The method has been adopted official first action by AOAC for determination of 800-1600 ppb fenbendazole In liver. The analysis should be repeated using a smaller sample size when Initial analyses show levels greater than 1600 ppb FBZ.

Stability-Indicating Liquid Chromatographic Determination of Alpha-Ionone in Toothpaste

1988 ◽  
Vol 71 (1) ◽  
pp. 36-37
Author(s):  
Ramesh J Trivedi
Keyword(s):  
Standard Deviation ◽  
Chromatographic Method ◽  
Cost Effective ◽  
Chromatographic Determination ◽  
Average Recovery ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple, sensitive, and rapid liquid chromatographic method for quantitating α-ionone in toothpaste at levels of 20 ppm in the presence of large amounts of flavor has been developed. The method is accurate, precise, cost-effective, and specific for α-ionone. Average recovery of a laboratory-prepared sample was 99.0% with the relative standard deviation was 1.29% (n = 6).

scholarly journals Liquid Chromatographic Method for Quantitation of Patulin at 10 ng/mL in Apple-Based Products Intended for Infants: Interlaboratory Study

2005 ◽  
Vol 88 (2) ◽  
pp. 518-525 ◽  
Author(s):  
Isabel Arranz ◽  
Michelle Derbyshire ◽  
Katy Kroeger ◽  
Carsten Mischke ◽  
Joerg Stroka ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Apple Juice ◽  
Liquid Chromatographic Method ◽  
Interlaboratory Trial ◽  
Relative Standard ◽  
Liquid Chromatographic ◽  
Research Facilities ◽  
Fruit Purée

Abstract An interlaboratory trial for the determination of patulin in apple juice and fruit puree was conducted, involving 17 participants representing a cross section of industry, official food control, and research facilities. Mean recoveries reported ranged from 74 (10 ng/g) to 62% (25 ng/g) for apple juice and from 72 (25 ng/g) to 74% (10 ng/g) for fruit puree. Based on results for spiked samples (blind pairs at 2 levels), as well as naturally contaminated samples (blind pairs at 3 levels), the relative standard deviation for repeatability (RSDr) in juice ranged from 8.0 to 14.3% and in puree from 3.5 to 9.3%. The relative standard deviation for reproducibility (RSDR) in juice ranged from 19.8 to 39.5% and in puree from 12.5 to 35.2%, reflecting HORRAT values from 0.6 to 1.0 for juice and 0.4 to 0.9 for puree. The method showed acceptable within-laboratory and between-laboratory precision for each matrix, as required by current European legislation.

scholarly journals Validation of a high-performance liquid chromatographic method with fluorecence detection for the quantification of flurbiprofen in tablets

2018 ◽  
Vol 34 (2) ◽  
Author(s):  
Thi Thanh Binh Nguyen ◽  
Anh Mai Tran ◽  
Thuan Hai Duong ◽  
Tung Huu Nguyen ◽  
Tung Thanh Bui
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
High Performance ◽  
Chromatographic Method ◽  
Limit Of Detection ◽  
High Performance Liquid Chromatographic ◽  
Intermediate Precision ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic

In this study, a high-performance liquid chromatographic method with fluorecence detection was developed for the quantification of flurbiprofen in tablets. A C8 reverse phase column (5 μm, 120 Å, 4.6×150 mm) was used with a mobile phase of acetonitrile : water : glacial acetic acid (65 : 32.5 : 2.5, v/v/v) . The flow rate was 1 ml/min and the column effluent was monitored within 8 minutes. The excitation and emission wavelength were respectively 247 nm and 312 nm. The temperature of flow cell was set at 45˚C and detector sensitivity was 5. The retention time of flurbiprofen was found to be 3.78 minutes. The method was validated under the concentration range of 5 - 100 ng/ml with a tight linear correlation between peak area and sample concentration (R = 0.9999). The proposed method was found to be specific to flurbiprofen, accurate and precise. The percentage recovery was ≤ 100 ± 2%, the relative standard deviation of the repeatability was ≤ 2.08% and the relative standard deviation of the intermediate precision was ≤ 2.96%. The limit of detection and limite of quantification were respectively 0.010 and 0.025 ng/ml.

Liquid Chromatographic Method for Determination of Azinphos-Methyl in Formulated Products: Collaborative Study

1988 ◽  
Vol 71 (5) ◽  
pp. 988-990
Author(s):  
Stephen C Slahck
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Azinphos Methyl ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Wettable Powder ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of azinphosmethyl (Guthion®) in formulated products has been developed. Samples are dissolved in acetonitrile and analyzed by reverse-phase chromatography using n-butyrophenone as an internal standard. The method was subjected to a collaborative study involving 15 participating laboratories. Each collaborator was furnished with reference standard, internal standard, and blind duplicate samples of Guthion 50% wettable powder (50WP), 3 flowable (3F), and emulsifiable concentrate (2L and 2S) formulations. Collaborators were instructed to evaluate the method by peak height measurements only. Relative standard deviations for reproducibility (RSDR) were 1.11, 6.28, 2.47, and 1.17% for the 50WP, 3F, 2L, and 2S formulations, respectively. The method has been approved interim official first action for determination of azinphos-methyl in the 50WP, 2L, and 2S formulations.

Liquid Chromatographic Method for Determination of Technical Deltamethrin and Deltamethrin in Pesticide Formulations: CIPAC Collaborative Study

1990 ◽  
Vol 73 (5) ◽  
pp. 751-752
Author(s):  
Alan R Hanks
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Liquid Chromatographic Method ◽  
Pesticide Formulations ◽  
Relative Standard ◽  
Aoac Method ◽  
Repeatability And Reproducibility ◽  
Low Volume ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of deltamethrin In 6 different technical and formulated products was collaboratively studied In 14 laboratories. Each sample Is dissolved In lsooctane-1,4-dloxane (80 + 20), separated by LC on a silica gel column (cyano column for ultra low volume formulation), and detected at 254 nm (230 nm for ≤0.5% powder formulations). Quantitation Is done by peak area measurements. Relative standard deviations for repeatability and reproducibility ranged from 0.56 to 1.00% and from 0.76 to 2.90%, respectively. The method has been approved Interim official first action by AOAC as a CIPAC-AOAC method.

Gas-Liquid Chromatographic Method for the Analysis of Microencapsulated Ethyl Parathion and Methyl Parathion Insecticides: Collaborative Study

1980 ◽  
Vol 63 (5) ◽  
pp. 999-1002 ◽  
Author(s):  
James J Karr ◽  
◽  
H D Antles ◽  
J B Audino ◽  
W R Bontoyan ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Chromatographic Method ◽  
Methyl Parathion ◽  
Collaborative Study ◽  
Internal Standard ◽  
Original Method ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Collaborative Efforts

Abstract The determination of ethyl parathion in Penncap-E insecticide was studied collaboratively by 14 laboratories. The assay of methyl parathion in Penncap-M insecticide was studied by 8 laboratories. The original method which was adopted official first action for methyl parathion specified dimethoate, which is currently classified as a suspected carcinogen, as the internal standard. The current collaborative efforts were conducted as a supplemental study to evaluate the performance of the new internal standard, bis-2-methoxyethyl phthalate, and to test the gas-liquid chromatographic method for microencapsulated ethyl parathion (internal standard, dibutyl phthalate). The method uses essentially the same grinding and extraction with acetonitrile as the original study. At the 20% methyl parathion level, the standard deviation within laboratories was 0.186%, and among laboratories, 0.737%. Two formulations of ethyl parathion at approximately 16 and 24% were analyzed in replicate on 2 days by the same analyst, and provided excellent agreement within laboratories as well as among laboratories. The standard deviation (pooled) within laboratories was 0.284% and among laboratories, 0.518%. The method has been adopted as official first action.

Liquid Chromatographic Method for Determination of Aflatoxins B1, B2, G1, and G2 in Corn and Peanut Products: Collaborative Study

1990 ◽  
Vol 73 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Douglas L Park ◽  
Stanley Nesheim ◽  
Mary W Trucksess ◽  
Michael E Stack ◽  
Richard F Newell
Keyword(s):  
Chromatographic Method ◽  
Peanut Butter ◽  
Collaborative Study ◽  
The United States ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Standard Deviations ◽  
Contamination Levels ◽  
Liquid Chromatographic

Abstract A collaborative study of a liquid chromatographic method for the determination of aflatoxins B1, B2, G1, and G2 was conducted in laboratories located in the United States, Canada, South Africa, and Switzerland. Twenty-one artificially contaminated raw peanuts, peanut butter, and corn samples containing varying amounts of aflatoxins B1, B2, G1, and G2 were distributed to participating laboratories. The test portion was extracted with methanol-0.1N HCl ( 4 + 1 ) , filtered, defatted with hexane, and then partitioned with methylene chloride. The concentrated extract was passed through a silica gel column. Aflatoxins B1 and G1 were derivatized with trifluoroacetic acid, and the individual aflatoxins were determined by reverse-phase liquid chromatography with fluorescence detection. Statistical analysis of the data was performed to determine or confirm outliers, and to compute repeatability and reproducibility of the method. For corn, relative standard deviations for repeatability (RSDr) for anatoxin B1 ranged from 27.2 to 8.3% for contamination levels from 5 through 50 ng/g. For raw peanuts and peanut butter, RSDr values for aflatoxin Bi were 35.0 to 41.2% and 11.2 to 19.1 %, respectively, for contamination levels from 5 through 25 ng/g. RSDr values for aflatoxins B2, G1, and G2 were similar. Relative standard deviations for reproducibility (RSDR) for aflatoxin B1 ranged from 15.8 to 38.4%, 24.4 to 33.4%, and 43.9 to 54.0% for corn, peanut butter, and raw peanuts, respectively. The method has been adopted official first action for the determination of aflatoxins B1, B2, G1, and G2 in peanut butter and corn at concentrations ≥13 ng total aflatoxlns/g.

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