Infrared Determination of Sorbic Acid in Foods

1965 ◽  
Vol 48 (4) ◽  
pp. 794-795
Author(s):  
George F Calloway ◽  
George Schwartzman
Keyword(s):  
Steam Distillation ◽  
Sorbic Acid ◽  
Collaborative Study ◽  
Food Product ◽  
Chloroform Extract ◽  
Food Samples ◽  
Infrared Method ◽  
Preliminary Study

Abstract Preliminary study of an infrared method for determination of sorbic acid in foods gave promising results. The procedure consists of steam distillation of the food product, extraction of the distillate with chloroform, and measurement of the infrared absorbance of the chloroform extract at 10 μ. Recoveries from 92 to 110% were obtained from 14 food samples spiked with 0.05–0.15% sorbic acid. A collaborative study is recommended.

Determination of Benzoates and Hydroxybenzoates in Foods

1966 ◽  
Vol 49 (4) ◽  
pp. 829-834 ◽  
Author(s):  
Salvatore J Pinella ◽  
Anthony D Falco ◽  
George Schwartzman
Keyword(s):  
Benzoic Acid ◽  
Steam Distillation ◽  
Sorbic Acid ◽  
Collaborative Study ◽  
Qualitative And Quantitative ◽  
Recording Spectrophotometer ◽  
Chromatographic Plate ◽  
Steam Distillation Extraction ◽  
Tlc Separation

Abstract A method has been devised for the qualitative and quantitative determination of benzoates and hydroxybenzoates in foods. The qualitative procedure is based on the TLC separation of benzoic acid, the hydroxybenzoates, and sorbic acid, using kieselguhr G-silica gel GF 254 as the absorbent and hexane:acetic acid as the mobile solvent. The separated preserving acids are identified under UV radiation and by specific chromogenic reagents. Benzoic acid in foods was determined quantitatively by steam distillation, extraction, and TLC separation. The benzoic acid was removed from the chromatographic plate, extracted with ethanol, and determined in the UV region with a recording spectrophotometer and 5 cm micro cells. These procedures should be subjected to collaborative study.

Collaborative Study of the Colorimetric Determination of Sorbic Acid in Cheese

1971 ◽  
Vol 54 (3) ◽  
pp. 663-665
Author(s):  
George Wilamowski
Keyword(s):  
Steam Distillation ◽  
Sorbic Acid ◽  
Potassium Dichromate ◽  
Collaborative Study ◽  
Thiobarbituric Acid ◽  
Colorimetric Determination ◽  
Red Color ◽  
Red Dye ◽  
532 Nm

Abstract After isolation of sorbic acid from cheese by steam distillation, the acid recovered is cleaved with potassium dichromate in acidic medium to form an intermediate malonaldehyde, which, in turn, reacts with 2-thiobarbituric acid to produce a red dye. The absorbance of the red color, measured at 532 nm, is proportional to the concentration of sorbic acid in the sample. Seven collaborators reported recoveries of 96.7–102.4% from cheese samples spiked with 0.05% sorbic acid. This method has been adopted as official first action.

Determination of Sorbic Acid in Wine

1974 ◽  
Vol 57 (4) ◽  
pp. 951-953
Author(s):  
Arthur Caputi ◽  
Masao Ueda ◽  
Bruno Trombella
Keyword(s):  
Steam Distillation ◽  
Acidic Solution ◽  
Sorbic Acid ◽  
Collaborative Study ◽  
Thiobarbituric Acid ◽  
Volatile Acid ◽  
Wine Analysis ◽  
Red Color ◽  
532 Nm

Abstract A survey of a number of laboratories engaged in wine analysis showed that 2 basic techniques were used for the determination of sorbic acid. The first utilizes the absorbance by sorbic acid at 260 nm in acidic solution and the second depends on the oxidation of sorbic acid to malonaldehyde which is then reacted with thiobarbituric acid. The resulting red color is measured at 532 nm. A modification of the thiobarbituric method has been adopted by AOAC for the determination of sorbic acid in cheese. We found it could be successfully utilized for sorbic acid analysis in wine with minor changes. It was necessary to separate the sorbic acid from wine by steam distillation prior to either determination. The standard Cash wine volatile acid still is adequate for this purpose and over 9 9% acid could be recovered from a 2 ml wine sample in 200 ml distillate. We studied various parameters in both techniques and arrived at practical procedures for each. Both methods gave acceptable results and we recommend that they be subjected to a collaborative study.

Colorimetric Determination of the Progestational Steroids in Contraceptive Tablets

1970 ◽  
Vol 53 (4) ◽  
pp. 831-833
Author(s):  
John Y P Wu
Keyword(s):  
Oral Contraceptive ◽  
Medroxyprogesterone Acetate ◽  
Collaborative Study ◽  
Chloroform Extract ◽  
Colorimetric Determination ◽  
Standard Deviations ◽  
Isonicotinyl Hydrazide ◽  
Norethindrone Acetate

Abstract Norethindrone, norethindrone acetate, dimethisterone, medroxyprogesterone acetate, and norethynodrel are determined in oral contraceptive tablets. For the first 4 compounds, a chloroform extract of the tablets is treated directly with isonicotinyl hydrazide reagent to produce a stable color which is measured at 380 nm. The chloroform extract of norethynodrel tablets is isomerized before the reagent is added. An intralaboratory study gave good results, with standard deviations of 0.74 to 1.21%. A collaborative study is recommended.

Determination of Hydroxybenzoates and Benzoates in Foods

1968 ◽  
Vol 51 (4) ◽  
pp. 876-877
Author(s):  
M H Lewis
Keyword(s):  
Quantitative Determination ◽  
Steam Distillation ◽  
Uv Spectroscopy ◽  
Collaborative Study ◽  
Solid Foods

Abstract A successful collaborative study was made on the determination of benzoates in solid foods, using the official, first action method for benzoates in liquid and semisolid foods. The method combines steam distillation, TLC, and UV spectroscopy. Recovery data ranged from 94 to 120%. An attempt to separate the parabens by GLC was successful but further work is needed for the quantitative determination of these compounds.

Determination of Nicotine in Feeds

1964 ◽  
Vol 47 (2) ◽  
pp. 226-228
Author(s):  
David E Root
Keyword(s):  
Aqueous Phase ◽  
Steam Distillation ◽  
Animal Feed ◽  
Collaborative Study ◽  
Basic Solution ◽  
Ultraviolet Spectrophotometry

Abstract Nicotine, used in medicated animal feed in combination with phenothiazine, dibutyl tin dilaurate, and 2,2'-dihydroxy-5,5’-dichlorophenyl methane, has been successfully isolated from these compounds and the feed interferences and cleaned up by extraction with 0.5% NaOH, steam distillation f r om this basic solution, and extraction from the aqueous phase with chloroform. The nicotine is then partitioned into 0.05iV HC1, and determined by ultraviolet spectrophotometry. A collaborative study yielded 9 0% over-all recoveries, and the method is recommended for adoption as official, first action.

Assessment of the Naphthylazo-naphthylamine Method for the Determination of Nitrate and Nitrite

1968 ◽  
Vol 51 (1) ◽  
pp. 140-147
Author(s):  
Len Kamm ◽  
D F Bray ◽  
D E Coffin
Keyword(s):  
Reproducibility Of Results ◽  
Statistical Data ◽  
Collaborative Study ◽  
Food Samples ◽  
Experimental Designs ◽  
Dye Reduction ◽  
Nitrate And Nitrite

Abstract The 1-naphthylazo-naphthylamine method for nitrate and nitrite, reported in 1965, was subjected to specific experiments statistically designed to determine more precisely the precision of the method. Experimental designs included the following: standard nitrite curve, stability of 1-naphthylazo- naphthylamino dye, reduction of nitrate to nitrite by the cadmium column, reproducibility of results comparing natural foodstuffs with pure solutions, and collaborative study on food samples. The statistical data obtained indicate that the method is consistent and precise

scholarly journals Determination Of Formaldehyde In Tofu From Ciputat Traditional Market With Colorimetry Method

2011 ◽  
Vol 2 (2) ◽  
Author(s):  
Zilhadia Zilhadia ◽  
Sanny Susanti
Keyword(s):  
Linear Regression ◽  
Calibration Curve ◽  
Analytical Method ◽  
Steam Distillation ◽  
Food Product ◽  
Extraction Process ◽  
Sample Extraction ◽  
Traditional Market ◽  
Nash Reagent

Tofu, a food product made from soybean, contain water and it is very easy to overgrown microbes.Based on a survey, many products of tofu contain formaldehyde as preservative. Formaldehyde is apreservative that the use is prohibited for food because it can cause cancer in humans. The aim of thisstudy was determined concentration of formaldehyde in tofu from traditional market Ciputat usingSpectrophotometer UVI-VIS. Steam distillation was used for sample extraction process. Distillate wasreacted with Nash reagent. The equation of calibration curve is y=0,0032x – 0,0079 and correlationcoefficient of the linear regression of 0,9992. The experimental results obtained LOD value of11.1328 μg/ml, LOQ value of 37,1094 μg/mL The precision of this analytical method were lower than2% for each of the sample, while method’s accuration for tofu was 98,69% ± 0,4085%. Results ofsample analysis from Ciputat market, samples were detected containing formaldehyde. Formaldehydeconcentrations are 104,87 μg/mL, 11,21 μg/mL, 1,96 μg/mL, 190,80 μg/mL, 201,98 μg/mL, 10,47μg/mL, and 3,31 μg/mL.

Collaborative Study of Infrared Methods for Phorate in Formulations

1964 ◽  
Vol 47 (2) ◽  
pp. 245-247
Author(s):  
N Kobekt Pasarela
Keyword(s):  
Collaborative Study ◽  
Infrared Method ◽  
Infrared Methods ◽  
Good Agreement

Abstract An infrared method for the determination of phorate in 5% and 10% granules was studied by 10 collaborators. In the method, the formulation is eluted from the carrier with acetonitrile, the solvent is removed by evaporation, and the residue is dissolved in cyclohexane. The absorbance of the solution is measured at 8.32 μ and the phorate content is determined by comparison with a sample of purified phorate treated in the same manner. Results show good agreement between replicates and laboratories. It is recommended that the method for phorate in granular formulations be adopted as official, first action.

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