Gas-Liquid Chromatographic Determination of Fluchloralin in Formulations

1977 ◽  
Vol 60 (5) ◽  
pp. 1145-1147
Author(s):  
Gregory S Grimes
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reference Standard ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) method has been developed that is precise, rapid, simple, and specific for fluchloralin in emulsifiable liquid formulation. Sample and reference standard are weighed, internal standard solution is added, and an aliquot of the mixture is injected onto the chromatographic column. Fluchloralin gives a sharp symmetrical peak at about 5.4 min. The internal standard has a broader symmetrical peak at about 6.9 min. The relative standard deviation for 21 consecutive injections of the standard solution was 0.3773%. The method was compared with the official GLC method, 6.210–6.215, for the structurally similar trifluralin. Fluchloralin gave a sharp symmetrical peak at about 8.5 min; the internal standard had a sharp symmetrical peak at about 9.2 min. The relative standard deviation of 21 consecutive injections of reference standard solution was 0.6988%. Comparison of the variances of the 2 methods by the F-test at the 99% confidence level showed that the proposed method demonstrated substantially better precision.

Liquid Chromatographic Determination of Narasin in Feed Premixes

1985 ◽  
Vol 68 (3) ◽  
pp. 417-418 ◽  
Author(s):  
Raymond L Hussey ◽  
Thomas D Macy ◽  
John Moran ◽  
Andrew Loh
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Chromatographic Determination ◽  
Bioassay Method ◽  
Water Solvent ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed to determine narasin in feed premixes. Narasin is extracted from the premix with a methanol-water solvent, and the extracted solution is assayed by using LC. Recovery of narasin from a 12.5 g/lb premix is quantitative (100%), with a relative standard deviation of 1.44%. The results correlated well (coefficient 0.92) with a turbimetric bioassay method.

scholarly journals Liquid Chromatographic Determination of Deoxynivalenol in Baby Food and Animal Feed: Interlaboratory Study

2006 ◽  
Vol 89 (4) ◽  
pp. 1012-1020 ◽  
Author(s):  
Joerg Stroka ◽  
Michelle Derbyshire ◽  
Carsten Mischke ◽  
Massimo Ambrosio ◽  
Katy Kroeger ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
High Performance ◽  
Animal Feed ◽  
Chromatographic Determination ◽  
Baby Food ◽  
Interlaboratory Study ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract An interlaboratory study was conducted for the determination of deoxynivalenol in baby food and animal feed by high-performance liquid chromatography with UV detection. The study included 14 participants representing a cross section of industry, official food control, and research facilities. Mean recoveries reported ranged from 89% (at 120 g/kg) to 85% (at 240 g/kg) for baby food and from 100% (at 200 g/kg) to 93% (at 400 g/kg) for animal feed. On the basis of the results for spiked samples (blind duplicates at 2 levels), as well as those for naturally contaminated samples (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) in analyses of baby food ranged from 6.4 to 14.0% and in analyses of animal feed, from 6.1 to 16.5%. The relative standard deviation for reproducibility (RSDR) in analyses of baby food ranged from 9.4 to 19.5% and in analyses of animal feed, from 10.5 to 25.2%. The HorRat values ranged from 0.4 to 1.0 and from 0.7 to 1.3, for baby food and animal feed, respectively. The method showed acceptable performance for within-laboratory and between-laboratory precision for each matrix, as required by European legislation.

Collaborative Study of the Gas-Liquid Chromatographic Determination of Bromoxynil Octanoate in Formulations

1978 ◽  
Vol 61 (5) ◽  
pp. 1158-1162
Author(s):  
Laurence J Helfant
Keyword(s):  
Standard Deviation ◽  
Acid Ester ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Improved Method ◽  
Liquid Chromatographic Determination ◽  
Chlorophenoxyacetic Acid ◽  
Liquid Chromatographic

Abstract The determination of bromoxynil octanoate by a gas-liquid chromatographic (GLC) method with di-n-butylphthalate as internal standard was subjected to testing by 10 collaborators. The standard deviation for bromoxynil octanoate and bromoxynil octanoate-MCPA (2-methyI- 4-chlorophenoxyacetic acid) ester formulations averaged 0.6%. While the deviation indicates that the method is statistically sound, the results were dependent upon the efficiency of the GLC column. Therefore, it is recommended that the method be subjected to continued study to further determine the GLC conditions necessary for improved method reliability.

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).

Gas-Liquid Chromatographic Determination of Bromoxynil Octanoate: Collaborative Study

1979 ◽  
Vol 62 (6) ◽  
pp. 1215-1219
Author(s):  
Laurence J Helfant ◽  
◽  
J Audino ◽  
G S Grimes ◽  
J J Karr ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Systematic Errors ◽  
Elution Time ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract The assay of bromoxynil octanoate by a gasliquid chromatographic (GLC) procedure with din-n-butylphthalate as the internal standard was previously subjected to collaboration. The method had a standard deviation of 0.6% but results varied according to the complexity of the formulaation being tested. To reduce the systematic errors of the method, the internal standard was changed to n-docosane. The change in elution time of the marker simplified the chromatogram and reduced the standard deviation of the study to 0.3%. The revised method has been adopted as official first action for determining bromoxynil octanoate.

scholarly journals Gas Chromatographic Determination of Acephate in Technical Material and Soluble Powder Formulations: Collaborative Study

1997 ◽  
Vol 80 (3) ◽  
pp. 459-463
Author(s):  
Martin F Kovacs ◽  
H Michael Wehr ◽  
B A Belkind ◽  
J Stein ◽  
O O Bennett ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Broad Spectrum ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reference Standard ◽  
Standard Samples ◽  
Relative Standard ◽  
Technical Material

Abstract A gas chromatographic (GC) method was developed for quantitation of acephate (Orthene) in technical material and soluble powder formulations. Acephate is an organophosphate with broad spectrum contact and systemic insecticidal properties. Fourteen collaborators from 8 countries participated in a collaborative study of the method. Collaborators were provided with the method; samples of technical acephate and formulated soluble powder containing 95-99% and 71-75% acephate, respectively; an acephate reference standard; and internal standard. Samples were weighed, diluted to volume with internal standard, and quantitated by using GC peak area ratios. Relative standard deviation values for reproducibility (RSDR) were 1.03-2.55 for 95-99% technical acephate and 1.36-2.73 for formulated soluble powder containing 71-75% acephate. The GC method for determination of acephate in technical material and soluble powder formulations has been adopted by AOAC INTERNATIONAL

Gas-Liquid Chromatographic Determination of Pentachloronitrobenzene in Pesticide Formulations

1976 ◽  
Vol 59 (3) ◽  
pp. 708-710
Author(s):  
Alan R Hanks ◽  
Christine W Cramer
Keyword(s):  
Chromatographic Method ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Liquid Chromatographic Method ◽  
Pesticide Formulations ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method has been developed to determine pentachloronitrobenzene (PCNB) in pesticide formulations including dusts, powders, granules, liquids, and fertilizers. Captan, disulfoton, and Terrazole do not interfere. Samples are extracted with chloroform, and an aliquot is mixed with an equal volume of internal standard solution containing o-terphenyl. PCNB is chromatographed on a 5% SE-30 column and quantitated by peak height ratios. The method has been subjected to a ruggedness test which indicates little sensitivity to changes in extraction and chromatographic conditions.

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.

Multiple Internal Standard Technique for the Gas-Liquid Chromatographic Determination of Indole in Shrimp

1978 ◽  
Vol 61 (1) ◽  
pp. 136-138
Author(s):  
Walter F Staruszkiewicz ◽  
John F Bond
Keyword(s):  
Silica Gel ◽  
Room Temperature ◽  
Internal Standard ◽  
Standard Technique ◽  
Chromatographic Determination ◽  
Experimental Conditions ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract A multiple internal standard technique has been developed for the official first action gas-liquid chromatographic (GLC) method for determining indole in shrimp. The modification was developed because interfering GLC peaks are occasionally observed when 2-methylindole is used as the internal standard. An internal standard solution containing 1-methylindole, 2- methylindole, and diphenylamine was added to extracts of shrimp before silica gel cleanup and separation by GLC. All of the compounds were quantitatively recovered and were separated on the GLC column under identical experimental conditions. Extracts of acceptable shrimp to which indole was added at levels of 3–10 μg/ 100 g and extracts of decomposed shrimp were stored at room temperature for 2 weeks. Average and maximum changes (μg indole/100 g) during storage were, respectively, for each internal standard: average 0.6, 0.4, and 1.1; maximum 1.7, 0.9, and 2.9.

Gas-Liquid Chromatographic Determination of Kepone Residues in Finfish, Shellfish, and Crustaceans

1978 ◽  
Vol 61 (4) ◽  
pp. 877-883
Author(s):  
Richard A Carver ◽  
Arnold P Borsetti ◽  
Laverne R Kamps
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Petroleum Ether ◽  
Ethyl Ether ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Finfish, shellfish, and crustacean samples are extracted with isopropanol and benzene; the extract is filtered and then concentrated. The extract, dissolved in hexane, is treated with oleum and extracted with aqueous alkali. The aqueous phase is acidified and extracted with petroleum ether-ethyl ether (1+1). The Kepone residue is determined by electron capture gas-liquid chromatography (GLC). Recoveries obtained by 8 laboratories from 15 species of finfish fortified at 0.02-0.23 ppm ranged from 37 to 107% with a mean ± relative standard deviation of 79.4±14.5%. For oysters fortified at 0.01- 0.10 ppm, recoveries range from 63 to 129% with a mean of 78.2 ±20.8%. For crustaceans fortified at 0.05—0.26 ppm, recoveries ranged from 52 to 110% with a mean of 78.8±16.4%. The approximate limits of quantitation for finfish and for shellfish and crustaceans are 0.02 and 0.05 ppm, respectively, under the GLC conditions used in this study.

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