Determination of Mercury in Biological Materials

Abstract Mercury in biological samples is determined by digestion in nitric acid, sulfuric acid, and permanganate, followed by reduction and aeration for measurement by atomic absorption at room temperature. The average recovery is 95.8% with a standard deviation of 13.3%. The standard deviation, calculated from the difference between duplicates of 23 samples, is 0.063 μg mercury, which represents 9.4% of the average value of the samples. The method is simple and requires approximately 4 hr for completion. Mercury can be confirmed by adsorption on gold foil after maximum absorbance has been obtained during aeration.

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Simple Combustion-Vapor Trapping Technique for Determination of Mercury in Fish

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/61.1.43 ◽

1978 ◽

Vol 61 (1) ◽

pp. 43-47

Author(s):

Fuad M Teeny

Keyword(s):

Standard Deviation ◽

Nitric Acid ◽

Mercuric Chloride ◽

Apparent Effect ◽

Average Recovery ◽

Sample Matrix ◽

Fish Samples ◽

Mercury In Fish

Abstract A simple combustion train was constructed for analyzing mercury in fish samples. A nitric acid trap was used to capture the mercury vapors which were released later by adding a tin salt. The method is rapid, accurate, and reproducible and permits one person to analyze 40 samples daily. Sample matrix had no apparent effect on the recovery of mercury. Mean recoveries from fish samples spiked with 0.3 and 1.0 μg mercuric chloride/g ranged from 97 to 105% with an average recovery of 101.5% and a standard deviation of 2.74%.

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Collaborative Study of the Automated Determination of Nitrogen in Meat Products

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/56.1.31 ◽

1973 ◽

Vol 56 (1) ◽

pp. 31-35 ◽

Cited By ~ 1

Author(s):

Walter M Gantenbein

Keyword(s):

Sulfuric Acid ◽

Standard Deviation ◽

Room Temperature ◽

Collaborative Study ◽

Meat Products ◽

Average Standard Deviation ◽

Colorimetric Measurement ◽

Average Coefficient ◽

Automated Determination

Abstract A modification of a previously reported method for nitrogen in meat products was subjected to collaborative study. Samples were dissolved in 1+1 sulfuric acid, cooled to room temperature, and presented to an Auto-Analyzer system. Digestion, dilution, and colorimetric measurement of nitrogen content were performed automatically. Seven collaborators participated in the study, analyzing 8 different samples in duplicate. Results of the study were satisfactory, with an average range of 0.95% protein, average standard deviation of ±0.39, and average coefficient of variation of 2.44%. The method has been found applicable to meat and meat products containing 0.8–4.0% nitrogen (5.0–25.0% protein).

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Determination of Fracture Toughness and K-R Curve for 2524-T3 Aluminum Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.291-294.1039 ◽

2011 ◽

Vol 291-294 ◽

pp. 1039-1042

Author(s):

Wei Xie ◽

Shao Wei Tu ◽

Qi Qing Huang ◽

Ya Zhi Li

Keyword(s):

Fracture Toughness ◽

Aluminum Alloy ◽

Stress Fracture ◽

Test Data ◽

Plane Stress ◽

Crack Extension ◽

Room Temperature ◽

Mode I ◽

Average Value

In the present work, the resistance to crack extension of 2524-T3 aluminum alloy under Mode I loading was studied by using the middle-cracked tension M (T) specimens. The curve, plane-stress fracture toughness and apparent plane-stress fracture toughness were calculated by test data. The average value of measured fracture toughness at room temperature was 161 MPam1/2. The results and conclusions can be referred in airplane skin design.

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Determination of Sodium Cromoglycate by a New Kinetic Spectrophotometric Method in Biological Samples

Journal of Chemistry ◽

10.1155/2013/206784 ◽

2013 ◽

Vol 2013 ◽

pp. 1-5

Author(s):

Mohsen Keyvanfard ◽

Khadijeh Alizad ◽

Razieh Shakeri

Keyword(s):

Standard Deviation ◽

Sodium Cromoglycate ◽

Spectrophotometric Method ◽

Calibration Curve ◽

Biological Samples ◽

Limit Of Detection ◽

Micellar Medium ◽

Relative Standard ◽

Kinetic Spectrophotometric

A new kinetic spectrophotometric method is described for the determination of ultratrace amounts of sodium cromoglycate (SCG). The method based on catalytic action of SCG on the oxidation of amaranth with periodate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of the amaranth at 518 nm, for the first 4 min from initiation of the reaction. Calibration curve was linear in the range of 4.0−36.0 ng mL−1SCG. The limit of detection is 2.7 ng mL−1SCG. The relative standard deviation (RSD) for ten replicate analyses of 12, 20, and 28 ng mL−1SCG was 0.40%, 0.32%, and 0.53%, respectively. The proposed method was used for the determination of SCG in biological samples.

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A sensitive spectrophotometric determination of tadalafil in pharmaceutical preparations and industrial wastewater samples

Baghdad Science Journal ◽

10.21123/bsj.10.3.1005-1013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 1005-1013 ◽

Cited By ~ 2

Author(s):

Baghdad Science Journal

Keyword(s):

Standard Deviation ◽

Industrial Wastewater ◽

Pharmaceutical Preparations ◽

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Average Recovery ◽

Relative Standard ◽

Wastewater Samples ◽

Sensitive Spectrophotometric Method

A simple, accurate, precise, rapid, economical and a high sensitive spectrophotometric method has been developed for the determination of tadalafil in pharmaceutical preparations and industrial wastewater samples, which shows a maximum absorbance at 204 nm in 1:1 ethanol-water. Beer's law was obeyed in the range of 1-7?g/ mL ,with molar absorptivity and Sandell ? s sensitivity of 0.783x105l/mol.cm and 4.97 ng/cm2respectively, relative standard deviation of the method was less than 1.7%, and accuracy (average recovery %) was 100 ± 0. 13. The limits of detection and quantitation are 0.18 and 0.54 µg .ml-1, respectively. The method was successfully applied to the determination of tadalafil in some pharmaceutical formulations (tablets) and industrial wastewater samples. The proposed method was validated by sensitivity and precision which proves suitability for the routine analysis of tadalafil in true samples.

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Thin Layer Densitometric Determination of Rotenone and Deguelin

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/52.1.182 ◽

1969 ◽

Vol 52 (1) ◽

pp. 182-187

Author(s):

Norman E Delfel ◽

William H Tallent

Keyword(s):

Acetic Acid ◽

Standard Deviation ◽

Nitric Acid ◽

Thin Layer ◽

Solvent System ◽

Ammonia Vapor ◽

Acid Vapor ◽

Tephrosia Vogelii ◽

Infrared Methods

Abstract Rutenone and deguelin are separated by chromatography on silver nitrate-impregnated silica gel G with chloroform acetone: acetic acid (196:3:1) solvent system. Glass plates, 20 × 20 cm, are coated with a special spreader producing a 0.25 mm layer and a 1.00 mm band at the upper end. Since additional solvent is required to saturate the thicker band, such plates give resolutions comparable to plates twice as long. Developed plates are treated with nitric acid vapor, then ammonia vapor, to produce dark spots for the rotenoids. Plates are scanned with a commercial densitometer, and the quantity of rotenoids is calculated from peak area in the resultant curve. Kecoveries of rotenone and deguelin added to extracts of Tephrosia vogelii, Lonchocarpus nicou, and Derris elliptica averaged 104.1 and 99.4%, respectively. The standard deviation of the method applied to plant extracts was 7.9% for rotenone and 8.3% for deguelin. The amounts of rotenone in the L. nicou samples were comparable to those determined by the AOAC crystallization and infrared methods.

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Spectrophotometric Method for Determination of Paraquat in Food and Biological Samples

Journal of AOAC International ◽

10.1093/jaoac/80.2.388 ◽

1997 ◽

Vol 80 (2) ◽

pp. 388-391 ◽

Cited By ~ 9

Author(s):

Ritu Kesari ◽

Manish Rai ◽

Vinay Kumar Gupta

Keyword(s):

Standard Deviation ◽

Metal Ions ◽

Relative Standard Deviation ◽

Alkaline Medium ◽

Spectrophotometric Method ◽

Biological Samples ◽

Molar Absorptivity ◽

Relative Standard ◽

Sensitive Spectrophotometric Method

Abstract A sensitive spectrophotometric method was developed for determination of paraquat, a widely used herbicide. Paraquat was reduced with glucose in an alkaline medium, and the blue radical ion obtained was measured at 600 nm. Beer’s law was obeyed at 0.1–1.2 ppm paraquat. The molar absorptivity was 1.26 × 105 L mol-1 cm-1. The standard deviation and relative standard deviation were ± 0.007 and 2.0%, respectively, for 5 μg paraquat/10 mL analyzed over 7 days. The method was free from interference by other commonly used pesticides and metal ions. The method may be used to the determine paraquat in plants, fruits, grains, water, blood, and urine.

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Determination of Inorganic Tin in Biological Samples by Hydride Generation-Atomic Absorption Spectrometry after Silica Gel Cleanup

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/71.2.373 ◽

1988 ◽

Vol 71 (2) ◽

pp. 373-374

Author(s):

Taizo Tsuda ◽

Minoru Wada ◽

Shigeru Aoki ◽

Yoshihiro Matsui

Keyword(s):

Standard Deviation ◽

Atomic Absorption Spectrometry ◽

Atomic Absorption ◽

Silica Gel ◽

Biological Samples ◽

Hydride Generation ◽

Absorption Spectrometry ◽

Fish Muscle ◽

Average Standard Deviation

Abstract A method is described for the determination of inorganic tin in biological samples by hydride generation-atomic absorption spectrometry (HG-AAS). A sample is extracted with ethyl acetate after addition of HC1 and NaCl. The concentrated extract is passed through a silica gel column. The column is washed with ethanol, water, and 0.2N HC1 successively, and then inorganic tin is eluted with 2N HC1 and measured by HG-AAS. Recoveries from fish muscle spiked with 0.1 ng/g Sn4+ are 78.9 ± 4.2% (average ± standard deviation, n = 5). The detection limit is 0.01 jug/g as Sn.

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Volumetric Determination of Malathion, Using Dichlorofluorescein as Indicator

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/59.1.216 ◽

1976 ◽

Vol 59 (1) ◽

pp. 216-218

Author(s):

Miguel Siquiroff ◽

Ricardo Pollero ◽

Rodolfo Goyena

Keyword(s):

Standard Deviation ◽

Petroleum Ether ◽

Silver Nitrate ◽

Ethyl Ether ◽

Colorimetric Method ◽

Florisil Column ◽

Average Recovery ◽

Florisil Column Chromatography ◽

Volumetric Determination

Abstract A method has been developed which is based on alkali cleavage of malathion and volumetric determination of the resulting dimethylphosphorodithioate with silver nitrate, using dichlorofluorescein as the indicator. Pure malathion standards were analyzed by the proposed method, yielding a standard deviation of 0.27. Four typical malathion formulations containing talc, wheat flour, and anionic and nonionic emulsifiers were analyzed by both the proposed method and the former official first action colorimetric method with comparable results. Potential interferences from surfactants currently employed in liquid formulations are avoided by the use of Florisil column chromatography. Malathion is eluted from the column with petroleum ether-ethyl ether with an average recovery of 92.5%.

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