Improved Method for Determination of Sulfites in Shrimp

1993 ◽  
Vol 76 (3) ◽  
pp. 565-569 ◽  
Author(s):  
Arantza Armentia-Alvarez ◽  
M Jesus Peña-Egedo ◽  
Concepcion Garcia-Moreno
Keyword(s):  
Aluminum Oxide ◽  
Improved Method ◽  
Edible Part ◽  
Coefficients Of Variation

Abstract A method for the determination of sulfites in shrimp developed by Kim and Kim and modified by Paino-Campa et al. for sausages has been further modified. Total sulfites are extracted by initially adding aluminum oxide to the sample and using an extraction solution at pH 12. In the reproducibility assays, coefficients of variation (CVs) were 4.8% for free sulfite and 7.8% for total sulfite in the edible part of the shrimp. In the inedible part, CVs were 7.5% and 8.9% for free and total sulfite, respectively. Mean recovery was 87.8% for the edible part and 84.4% for the inedible part of the shrimp. The method was compared with the optimized Monier- Williams method. The results obtained with both methods for determination of total SO2 in the edible part of the shrimp did not show significant differences (P= 0.05).

Quantitative Determination of Coumestrol in Dried Alfalfa and Alfalfa Leaf Protein Concentrates Containing Chlorophyll

1975 ◽  
Vol 58 (5) ◽  
pp. 983-986
Author(s):  
Benny E Knuckles ◽  
Raymond E Miller ◽  
E M Bickoff
Keyword(s):  
Quantitative Determination ◽  
Analytical Method ◽  
Leaf Protein ◽  
Improved Method ◽  
Alcohol Extract ◽  
Protein Concentrates ◽  
Coefficients Of Variation ◽  
Lower Standard ◽  
Alfalfa Leaf

Abstract An improved analytical method for the determination of coumestrol in dried alfalfa and leaf protein concentrates is described. In this method, chlorophyll is removed from an alcohol extract prior to the paper chromatographic-fluorometric measurement of coumestrol. Ninety-eight per cent of the coumestrol added to alfalfa leaf protein concentrates is recovered by this method. This improved method gives replicate values with lower standard deviations and coefficients of variation than the literature method.

scholarly journals Improved Method for Determination of Abamectin and Ivermectin in Cattle Plasma

2001 ◽  
Vol 84 (6) ◽  
pp. 1730-1734
Author(s):  
Guang Zhi Wei ◽  
Jun Suo Li
Keyword(s):  
Fluorescence Detection ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Trifluoroacetic Anhydride ◽  
Improved Method ◽  
Alumina Column ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic ◽  
Fluorescent Derivative

Abstract A liquid chromatographic (LC) method was developed for determination of abamectin (ABM) and ivermectin (IVM) in cattle plasma. The sample was extracted with acetonitrile and cleaned up on an alumina column. After conversion to stable fluorescent derivative with trifluoroacetic anhydride and N-methylimidazole, the sample was analyzed by LC with fluorescence detection (Ex 365 nm and Em 475 nm). Doramectin was used as an internal standard. Recoveries ranged from 91.2 to 100.7% for IVM and from 87.0 to 98.7% for ABM, with 1–50 ng/mL fortified samples. The coefficients of variation were <10.1%. The limit of detection was 0.02 ng/mL for ABM and IVM in 1.0 mL samples.

scholarly journals An Improved Method for Measurement of Common Tricyclic Antidepressant Drugs and their Metabolites Using Normal Phase HPLC

1986 ◽  
Vol 23 (5) ◽  
pp. 552-558 ◽  
Author(s):  
J D Blakesley ◽  
C G Howse ◽  
J Spencer-Peet ◽  
D C F Wood
Keyword(s):  
Antidepressant Drugs ◽  
Hplc Method ◽  
Tricyclic Antidepressant ◽  
Normal Phase ◽  
Good Recovery ◽  
Improved Method ◽  
Coefficients Of Variation ◽  
Silica Cartridge ◽  
Normal Phase Hplc

A sensitive HPLC method that allows the simultaneous determination of imipramine, amitriptyline and their desmethyl metabolites, using a 10 cm straight silica cartridge column with a mobile phase consisting of 0·004% perchloric acid in methanol is presented. Detection of the eluent is at 210 nm. The drugs are back-extracted from serum, giving both a good recovery and sensitivity of at least 5 μg/L. This method has proved to be extremely robust and reliable, with coefficients of variation around 3% being reported.

SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

1973 ◽  
Vol 72 (4) ◽  
pp. 714-726 ◽  
Author(s):  
A. Burger ◽  
B. Miller ◽  
C. Sakoloff ◽  
M. B. Vallotton
Keyword(s):  
Ionic Strength ◽  
Limit Of Detection ◽  
Improved Method ◽  
Accuracy Of Measurement ◽  
Tracer Amount ◽  
The Mean ◽  
Physiological Values ◽  
Hyperthyroid Patients ◽  
Solvent Blank

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

An Improved Method for the Determination of Metabolic Fecal P

1957 ◽  
Vol 16 (1) ◽  
pp. 201-206 ◽  
Author(s):  
J. R. Luick ◽  
G. P. Lofgreen
Keyword(s):  
Improved Method

Improved Method for the Determination of Ethylenebisdithiocarbamate Residues in Plants, Fruits, and Vegetables

1967 ◽  
Vol 50 (5) ◽  
pp. 1102-1108
Author(s):  
Charles F Gordon ◽  
Richard J Schuckert ◽  
William E Bornak
Keyword(s):  
Sulfuric Acid ◽  
Fruits And Vegetables ◽  
Analytical Procedure ◽  
Improved Method ◽  
Modified Method ◽  
Fungicide Residues ◽  
Crop Types ◽  
Large Representative

Abstract A modified method for the determination of dithiocarbamate fungicide residues on crops is presented. A large representative subsample of the frozen crop is blended in ice-cold deaerated water and an aliquot of the homogenate is added to the analytical apparatus containing hot 5 0% sulfuric acid. Dithiocarbamates are decomposed to evolve CS2 which is removed by a continuous gentle air-sweep from the digestion flask. Variations in technique allow the analysis of dithiocarbamate fungicide residues in several ranges, 1-10, 10-200, and 200-1000 /ig maneb. Recoveries from a wide variety of crops averaged 70 to 103%. Certain crop types present low recoveries and/or high apparent control values, but modifications in the analytical procedure are successful in solving these problems.

scholarly journals Directly ageing the Caribbean spiny lobster, Panulirus argus with validated band counts from gastric mill ossicles

2018 ◽  
Vol 76 (2) ◽  
pp. 442-451 ◽  
Author(s):  
Gaya Gnanalingam ◽  
Mark J Butler ◽  
Thomas R Matthews ◽  
Emily Hutchinson ◽  
Raouf Kilada
Keyword(s):  
Spiny Lobster ◽  
Age Determination ◽  
Florida Keys ◽  
Panulirus Argus ◽  
Gastric Mill ◽  
Coefficients Of Variation ◽  
The Caribbean ◽  
First Time ◽  
Reader Experience

Abstract In crustaceans, ecdysis was long believed to result in the loss and replacement of all calcified structures, precluding the use of conventional ageing methods. However, the discovery of bands in the gastric ossicles of several crustaceans with some correlation with age suggests that direct age estimation may be possible. We applied this method to a tropical spiny lobster, Panulirus argus, one of the most iconic and economically valuable species in the Caribbean. The presence of growth bands was investigated using wild lobsters of unknown age and was validated with captive reared lobsters of known age (1.5–10 years) from the Florida Keys, Florida (USA). Bands were consistently identified in ptero- and zygo-cardiac ossicles of the gastric mill and did not appear to be associated with moulting. Validation with known age animals confirms that bands form annually. Counts between independent readers were reproducible with coefficients of variation ranging from 11% to 26% depending on reader experience and the structure used. This study demonstrates, for the first time, that direct age determination of P. argus is possible.

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