Determination of Total Arsenic in Total Diet Samples

1970 ◽  
Vol 53 (6) ◽  
pp. 1176-1178
Author(s):  
Harvey K Hundley ◽  
Joseph C Underwood
Keyword(s):  
Acid Solution ◽  
Magnesium Oxide ◽  
Food Samples ◽  
Magnesium Nitrate ◽  
Total Arsenic ◽  
Wide Range ◽  
Total Diet

Abstract A simple, sensitive, and reproducible procedure has been investigated for the determination of total arsenic in composite food samples. Samples are dry ashed in the presence of magnesium oxide and magnesium nitrate, and arsenic is evolved from an acid solution as its hydride. The arsine is reacted with silver diethyldithiocarbamate to give a red complex that is measured photometrically. The absorbance of this complex is proportional to arsenic over a wide range of concentrations (1–20 μg arsenic). The method presented is sensitive to 0.05 ppm (1 μg/20 g product).

Dry Ashing Method for the Determination of Total Arsenic in Poultry Tissues

1969 ◽  
Vol 52 (5) ◽  
pp. 930-932
Author(s):  
Joseph L Morrison ◽  
Glenn M George
Keyword(s):  
Magnesium Oxide ◽  
Magnesium Nitrate ◽  
Arsenic Content ◽  
Total Arsenic ◽  
Tissue Samples ◽  
Dry Ashing ◽  
Poultry Tissues

Abstract A method is described for the determination of arsenic in poultry tissue, which is sensitive to levels of less than 0.1 ppm. Tissue samples are dry-ashed in the presence of magnesium oxide and magnesium nitrate and the arsenic is determined colorimetrically with silver diethyldithiocarbamate. Arsenic content in the tissue is determined from standard curves prepared for each tissue; this technique corrects for losses during the ashing step.

Graphite Furnace Atomic Absorption Method for the Determination of Chromium in Foods and Biological Materials

1992 ◽  
Vol 75 (2) ◽  
pp. 354-359 ◽  
Author(s):  
N J . Miller Ihli ◽  
F E Greene
Keyword(s):  
Atomic Absorption ◽  
Graphite Furnace ◽  
Absorption Spectrometry ◽  
Biological Materials ◽  
Food Samples ◽  
Magnesium Nitrate ◽  
Matrix Modifier ◽  
Graphite Furnace Atomic Absorption ◽  
Characteristic Mass

Abstract A method was developed for the determination of chromium in food samples and other biological materials. Samples are dry ashed In a muffle furnace and are analyzed by graphite furnace atomic absorption spectrometry. Magnesium nitrate is used as a matrix modifier, and samples are quantltated by platform atomizatlon and peak area measurements with direct calibration against aqueous standards. The detection limit (based on 3.29 σ) was 5.6 pg, or 0.28 μg/L for a 20 μL injection. The characteristic mass was 3.2 pg. This method was validated by analyzing a range of reference materials and was subsequently used for the analysis of a variety of food samples. A comparison of analytical results obtained from direct calibration and method of additions was made.

Digestion of Food Samples for Total Mercury Determination

1985 ◽  
Vol 68 (5) ◽  
pp. 891-893
Author(s):  
Hon Way Louie ◽  
Danny Go ◽  
Mara Fedczina ◽  
Kevin Judd ◽  
John Dalins
Keyword(s):  
Detection Limit ◽  
Total Mercury ◽  
Inorganic Mercury ◽  
Food Samples ◽  
National Bureau ◽  
Mercury Determination ◽  
Albacore Tuna ◽  
Wide Range

Abstract A method of digestion by using a mixture of hydrochloric, nitric, and sulfuric acids has been developed for the determination of total mercury in a wide range of food samples. Good recoveries of mercury were obtained from NBS (National Bureau of Standards) Albacore Tuna and from food samples spiked with inorganic mercury. A detection limit of 0.01g mercury/g can be obtained.

Mixed Acid Solubilization Procedure for Determination of Total Mercury in Food Samples

1983 ◽  
Vol 66 (6) ◽  
pp. 1421-1423
Author(s):  
Ronald W Marts ◽  
John J Blaha
Keyword(s):  
Total Mercury ◽  
Food Samples ◽  
Carbohydrate Content ◽  
Mixed Acid ◽  
Food Items ◽  
Wide Range

Abstract A mixed acid solubilization procedure has been developed for the determination of total mercury in food samples. This procedure has eliminated the problem of mercury loss from samples that are high in lipid or carbohydrate content. The solubilization is rapid and quantitative and can be used for a wide range of food items.

scholarly journals Determination of Total Iodine in Food Samples Using Inductively Coupled PlasmaMass Spectrometry

2009 ◽  
Vol 92 (6) ◽  
pp. 1720-1727 ◽  
Author(s):  
Karima Benkhedda ◽  
André Robichaud ◽  
Stéphane Turcotte ◽  
Franca J Béraldin ◽  
Kevin A Cockell
Keyword(s):  
Certified Reference Materials ◽  
Food Samples ◽  
Total Iodine ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Total Diet ◽  
Canadian Market ◽  
Replicate Measurements ◽  
Composite Samples

Abstract A method was developed and validated for the extraction and determination of total iodine (I) in food composite samples, representing different foods available on the Canadian market, by inductively coupled plasmamass spectrometry (ICP-MS). Prior to analysis, samples were digested in a closed microwave system using a mixture of nitric acid and perchloric acid. The detection limit for iodine determination was 29 ng/g and precisions of 10 and 1.3 were obtained for 10 replicate measurements of 100 and 1000 ng/g standards, respectively. The method was validated using Certified Reference Materials and spike recovery measurements in food samples and was applied for the determination of iodine in a variety of food composite samples from the Canadian Total Diet Study. The high sample throughput of ICP-MS makes the method suitable for analysis of large numbers of food samples with varying matrixes, such as for Total Diet Studies.

Direct Fluorometric Determination of Urea in Urine

1972 ◽  
Vol 18 (5) ◽  
pp. 476-478 ◽  
Author(s):  
Joon H Rho
Keyword(s):  
Acid Solution ◽  
Urea Concentration ◽  
Fluorometric Method ◽  
Fluorometric Determination ◽  
Wide Range

Abstract In this quantitative fluorometric method, diacetylmonoxime is used for the determination of the urea. The products of the reaction of urea with diacetylmonoxime in acid solution exhibit two fluorescence maxima, at 410 and 525 nm. The intensity of the 525 nm maximum is linear over a wide range of urea concentration and the reaction is shown to be practically specific for urinary urea.

scholarly journals A highly sensitive and selective spectrofluorimetric method for the determination of molybdenum at pico-trace levels in various matrices using N-(pyridin-2-yl)-quinoline-2-carbothioamide

2021 ◽  
Vol 12 (1) ◽  
pp. 1-12
Author(s):  
Muhammad Jamaluddin Ahmed ◽  
Ayesha Afrin ◽  
Muhammad Emdadul Haque
Keyword(s):  
Certified Reference Materials ◽  
Biological Fluids ◽  
Reaction System ◽  
Bovine Liver ◽  
Food Samples ◽  
Complexing Agents ◽  
Linear Calibration ◽  
Spectrofluorimetric Method ◽  
Wide Range

A new spectrofluorimetric reagent N-(pyridin-2-yl)-quinoline-2-carbothioamide (PQTA) has been synthesized and characterized. A very simple, ultra-sensitive, and highly selective, and non-extractive new spectrofluorimetric method for the determination of molybdenum at pico-trace levels using PQTA has been developed. This novel fluorimetric reagent PQTA, becomes oxidized in a slightly acidic (0.0025-0.05 M H2SO4) solution with molybdenum (VI) in absolute ethanol to produce a highly fluorescent oxidized product (λex = 300 nm; λem= 377 nm). Constant and maximum fluorescence intensities were observed over a wide range of acidity (0.0025-0.0500 M H2SO4) for the period between 2 min and 24 h. Linear calibration graphs were obtained for 0.001-600 μg/L of Mo having a detection limit of 0.15 ng/L; the quantification limit of the reaction system was found to be 1.5 ng/L and the RSD was 0-2%. A large excess of over 60 cations, anions, and complexing agents like chloride, phosphate, azide, tartrate, oxalate, and SCN- etc. do not interfere in the determination. The developed method was successfully used in the determination of molybdenum in several Certified Reference Materials (Alloys, steel, serum, bovine liver, drinking water, soil, and sediments) as well as in some environmental waters (Potable and polluted), biological fluids (Human blood, urine, hair, and milk), soil samples and food samples (Vegetables, rice, and wheat) solutions containing both molybdenum (VI) and molybdenum (V) ions. The results of the proposed method for assessing biological, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement.

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