scholarly journals Aluminon: its limited application as a reagent for the detection of aluminum species.

1985 ◽  
Vol 33 (7) ◽  
pp. 729-732 ◽  
Author(s):  
R A Clark ◽  
G L Krueger
Keyword(s):  
Tricarboxylic Acid ◽  
Histochemical Staining ◽  
Spectrophotometric Analysis ◽  
Colorimetric Determination ◽  
Pertinent Literature ◽  
Color Formation ◽  
Color Development ◽  
Inorganic Species ◽  
Limited Application

The triammonium salt of aurin tricarboxylic acid, commonly referred to as aluminon, forms a dye that has been used for the colorimetric determination of Al(III) species. We have reviewed the pertinent literature on the reaction of aluminon with respect to the metallic species that form colored aluminon complexes. The effects of experimental variables, such as time, temperature, and pH, upon the color development of the aluminon complex are also presented. Organic and inorganic species, particularly Be(II) and Fe(III), which can affect color formation, are described. The use of aluminon as a histochemical staining agent for the detection of aluminum requires verification by atomic absorption spectrophotometric analysis or other quantitative techniques.

Colorimetric Determination of Aklomide (2-Chloro-4-Nitrobenzamide) in Poultry Feed

1969 ◽  
Vol 52 (3) ◽  
pp. 438-441
Author(s):  
Glenn M George ◽  
A C Daftsios ◽  
Joseph L Morrison
Keyword(s):  
Nitro Group ◽  
Poultry Feed ◽  
Colorimetric Determination ◽  
Average Recovery ◽  
Low Level ◽  
Color Development ◽  
Titanium Trichloride ◽  
High Level

Abstract The coccidiostat aklomide is extracted from feed with methanol and assayed colorimetrically by reduction of the nitro group to anamine with titanium trichloride and subsequent color development with t he Bratton-Marshall reaction. Thirteen laboratories studied the method collaboratively on two levels of medicated feed. Overall average recovery was 106.5% of the oretical for the low level and 104.5% of the oretical for the high level. The method is recommended for adoption as official first action

Detection of Sprouted Wheat by a Rapid Colorimetric Determination of α-Amylase

1977 ◽  
Vol 60 (1) ◽  
pp. 16-20 ◽  
Author(s):  
Paul R Mathewson ◽  
Yeshajahu Pomeranz
Keyword(s):  
Incubation Time ◽  
Spectrophotometric Analysis ◽  
Colorimetric Determination ◽  
Visual Comparison ◽  
Laboratory Facilities

Abstract A method is described for the rapid, convenient detection or estimation of sprout-damaged wheat by determining its α-amylase content colorimctrically. A commercially available substrate in the form of dyed amylose tablets is used. The extent of sprout damage can be determined qualitatively, or quantitatively when actual α-amylase concentration is required. Amylase content is determined by visual comparison with prepared colored standards or by spectrophotometric analysis. The method requires only 5 min incubation time and no elaborate equipment, and is sufficiently simple for use at locations having minimal laboratory facilities.

Sensitive Colorimetric Determination of Cholesterol in Dairy Products

1976 ◽  
Vol 59 (5) ◽  
pp. 1146-1149 ◽  
Author(s):  
Kermit C Bachman ◽  
Jan-Hai Lin ◽  
Charles J Wilcox
Keyword(s):  
Dairy Products ◽  
Skim Milk ◽  
Raw Milk ◽  
Colorimetric Determination ◽  
Hexane Extraction ◽  
Color Development ◽  
Fat Extraction ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic

Abstract Cholesterol can be determined colorimetrically in dairy products at levels of ≥10 μg (coefficient of variation = 5.3%) with an o-phthalaldehyde reagent when non-cholesterol lipids arc eliminated prior to color development. Absorbance for 2 mg tripalmitin was found to be equivalent to about 20 μg cholesterol. Saponification followed by hexane extraction removed interfering lipids. Using the described procedure, 238 individual raw milk samples were found to contain 144.4±37.9 μg cholesterol/ml, while their skim milk portions had 26.5±6.4 μg cholesterol/ml (mean ± standard deviation). The o-phthalaldehyde cholesterol estimates agreed with those obtained by a gas-liquid chromatographic procedure when cheese and ice cream were analyzed by the colorimetric procedure with and without prior fat extraction.

scholarly journals Colorimetric determination of trace amounts of iron in uranium by the color development in the solvent layer

1961 ◽  
Vol 10 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Takayoshi YOSHIMORI ◽  
Yoshirô TOMIDA ◽  
Tsugio TAKEUCHI
Keyword(s):  
Colorimetric Determination ◽  
Color Development ◽  
Solvent Layer

Colorimetric Determination of Boric Acid in Prawns, Shrimp, and Salted Jelly Fish by Chelate Extraction with 2-Ethyl-l,3-Hexanediol

1979 ◽  
Vol 62 (3) ◽  
pp. 610-614
Author(s):  
Shunjiro Ogawa ◽  
Masatake Toyoda ◽  
Yasuhide Tonogai ◽  
Yoshio Ito ◽  
Masahiro Iwaida
Keyword(s):  
Boric Acid ◽  
Butyl Acetate ◽  
Official Method ◽  
Colorimetric Determination ◽  
Reduced Pressure ◽  
Color Development ◽  
Fish Detection ◽  
Frozen Shrimp ◽  
Acetate Mixture

Abstract Borate was directly chelate-extracted from foods with 5% 2-ethyl-l,3-hexanediol (EHD) in n-hexane–n-butyl acetate mixture (8+2), from which borate was selectively transferred into 1% NaOH, since EHD-chelated boron did not react with curcumin to develop color. Finally, an aliquot of the alkaline solution was acidified with HC1 and reacted with curcumin in a rotary evaporator. Color development was increased by heating for 8 min at 80°C under reduced pressure of 16 mm Hg. Frozen shrimp and prawns (peeled and with shells) and salted jelly fish were analyzed by the proposed method. Results were compared with the contemporary official method of Japan based on curcumin reaction on an incinerated sample. Over 90% of the boric acid was recovered by the proposed method when samples were fortified with 20 ppm boric acid. Recoveries were superior to those of the official method especially for shrimp and prawns with shells and salted jelly fish. Detection limit of boric acid is 1 ppm. Moreover, the method requires only about 1 hr for analysis of one sample, making it suitable for routine analysis.

Chemical Test for Mammalian Feces: Collaborative Study

1981 ◽  
Vol 64 (1) ◽  
pp. 196-198
Author(s):  
Joel J Thrasher ◽  
John S Gecan ◽  
◽  
R Bradicich ◽  
M Chaput ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Chemical Method ◽  
Collaborative Study ◽  
Basic Medium ◽  
Correct Identification ◽  
Colorimetric Determination ◽  
Chemical Test ◽  
Color Development

Abstract A chemical method was developed to determine the presence of mammalian feces in food. The method consisted of the colorimetric determination of alkaline phosphatase and involved the splitting of the phosphate radical from phenolphthalein diphosphate and the resultant color development of phenolphthalein in a basic medium. A collaborative study testing the feces of 22 animals resulted in a 95% correct identification of samples as mammalian feces. The method has been adopted official first action.

PHOTOMETRIC STUDIES ON THE DIAZO REACTION FOR SERUM BILIRUBIN

1952 ◽  
Vol 30 (6) ◽  
pp. 552-560
Author(s):  
F. D. White ◽  
Dorothea Duncan
Keyword(s):  
Sodium Salt ◽  
Calibration Curve ◽  
Serum Bilirubin ◽  
Alcohol Solution ◽  
Color Intensity ◽  
Color Formation ◽  
Color Development ◽  
Beer's Law ◽  
Beer’S Law

Photometric studies on the Malloy-Evelyn procedure for the determination of serum bilirubin have shown that the azobilirubin color intensity obtained when the diazo reagent acts for 30 min. upon a known amount of bilirubin added to serum in the form of the sodium salt is less than when the reaction takes place with the same amount of bilirubin in chloroform-alcohol solution. This suggests that the usual calibration curve prepared from bilirubin in chloroform-alcohol solution, when used as standard for serum bilirubin determinations, may give values which are about 10% less than the true bilirubin content of the serum. It has also been shown that with the 1 : 10 dilution of the Malloy-Evelyn procedure the azobilirubin from icteric sera does not obey Beer’s law beyond a serum bilirubin content of 15 mgm. per 100 ml. Evidence is submitted that the rate of azobilirubin color formation can be markedly accelerated by increasing the strength of the diazo reagent, and a new reagent is proposed by the use of which the time of color development can be reduced from 30 min. to 5 min.

Comparison of Two Methods and Improvements for Colorimetric Determination of Nitrite in Cod Roe

1979 ◽  
Vol 42 (9) ◽  
pp. 715-718 ◽  
Author(s):  
YOSHIO ITO ◽  
MICHIYO YODOSHI ◽  
JUN-ICHI TANAKA ◽  
MASAHIRO IWAIDA
Keyword(s):  
Meat Products ◽  
Reference Method ◽  
Coupling Reaction ◽  
Original Method ◽  
Colorimetric Determination ◽  
Modified Method ◽  
Color Development ◽  
Reproducible Method ◽  
Ppm Level

Attempts were made to develop a sensitive and reproducible method to determine nitrite in cod roe. Two diazotation-coupling reaction methods were considered; (a) the method defined by the Ministry of Health and Welfare of Japan (Method 1) and (b) the reference method of ISO (Method 2). Since the nitrite content in cod roe was much less than in meat products, Method 2 was modified to make it suitable for microanalysis at 1 ppm level as NO2. Modifications included reducing volumes of color-development solutions and making changes in the color development process, thus making the color intensity four times as great as before. Carrying out corrections with both reagent and water blanks made the effect of the blank on measured values negligible. Recoveries of nitrite at 20- and 2-ppm levels were 94.7 and 88.1%, respectively, reproducibility being ± 7 .9%, as the coefficient of variation. The obtained values by the modified method were, on the average, higher than those of the original method by 37.1%. Nitrite contents obtained by Method 1 were lower than those by the original Method 2. These low values might be attributed to loss of nitrite during extraction from the sample without pH adjustment, since the measured value showed a remarkable increase by addition of alkaline solution before extraction. Nitrite contents in imported cod roe were within the range 0.16–1.03 ppm expressed as NO2.

Colorimetric Determination of 2,6-Dichloro-4-Nitroaniline (Dichloran) Residues in Foods

1969 ◽  
Vol 52 (4) ◽  
pp. 797-799
Author(s):  
James A Heagy
Keyword(s):  
Colorimetric Method ◽  
Chromatographic Column ◽  
Colorimetric Determination ◽  
Modified Method ◽  
Color Development ◽  
Development Procedure

Abstract The colorimetric method of Groves and Chough for determining dichloran residues in food was modified. The modified method uses a Florisil chromatographic column cleanup and a Bratton-Marshall color development procedure. Recoveries ranged from 90 to 100% for eight crops. The method is recommended for further study.

Optimization of Conditions for Accurate Phosphonate and Total Phosphorus Assay on Lipid Samples, in Conjunction with Thin-Layer Chromatography

1986 ◽  
Vol 41 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Vassilios M. Kapoulas ◽  
George Th. Tsangaris
Keyword(s):  
Accurate Determination ◽  
Ammonium Molybdate ◽  
Inorganic Acid ◽  
Color Formation ◽  
Color Development ◽  
Phosphomolybdenum Blue ◽  
Layer Chromatography ◽  
Total P ◽  
Separate Calibration

The range of inorganic acid normalities for maximum color formation of the phosphomolybdenum- blue complex (under heating) increases by elevating the ammonium molybdate concentration, and at a ratio of molybdate molarity/acid normality equal to 10, there is maximum color development at any acid normality in the range 1-4 ɴ with either HClO4 or H2SO4 (or their mixtures). On the basis of these features a revised method is described for the accurate determination of phosphonate-P percent of total-P. on lipid extracts and on TLC bands. The color at the final step, in both cases, is developed under the same conditions of molybdate, HClO4 and H2SO4 concentrations, thus avoiding possible errors produced by the use of two separate calibration curves.

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