Evaluation of Color Additives Using a Differential Scanning Calorimeter

1970 ◽  
Vol 53 (2) ◽  
pp. 244-249
Author(s):  
Daniel M Marmion
Keyword(s):  
Melting Point ◽  
Moisture Content ◽  
Differential Scanning Calorimeter ◽  
Relative Stability ◽  
Heat Of Fusion ◽  
Permanent Record ◽  
Natural Color ◽  
Sensitive Tool ◽  
Similar Information

Abstract DSC is a rapid and sensitive tool for the determination of the melting point, moisture content, purity, and heat of fusion of certifiable colors. The relative stability and the identification of the colorants may also be deduced from the thermograms. The procedures outlined require only a few milligrams of sample and provide a permanent record. Attempts to obtain similar information for natural color additives were unsuccessful due to the inability to obtain reproducible thermograms.

scholarly journals The variation with temperature of the specific heat of sodium in the solid and the liquid state; also a determination of its latent heat of fusion

1914 ◽  
Vol 89 (614) ◽  
pp. 561-574 ◽  
Keyword(s):  
Melting Point ◽  
Specific Heat ◽  
Latent Heat ◽  
Liquid State ◽  
Mean Value ◽  
Heat Of Fusion ◽  
Latent Heat Of Fusion ◽  
The Mean ◽  
Considerable Range

The present paper contains the results of an investigation into the variation, with temperature, of the specific heat of sodium in the solid and the liquid state; also, some determinations of its latent heat of fusion. Our knowledge of the variations of the specific heat of metals in the region of their melting point is extremely vague and hypothetical, since the methods of investigation commonly employed are only capable of giving the mean value of the specific heat over a considerable range of temperature.

EINE CHEMISCHE METHODE ZUR BESTIMMUNG VON 16-EPI-ÖSTRIOL IM URIN DES MENSCHEN

1963 ◽  
Vol 44 (1) ◽  
pp. 47-66 ◽  
Author(s):  
W. Nocke ◽  
H. Breuer
Keyword(s):  
Melting Point ◽  
Phosphoric Acid ◽  
Aqueous Alkali ◽  
Percentage Error ◽  
Organic Layer ◽  
Maximum Percentage ◽  
Chemical Determination ◽  
Routine Assay ◽  
Hydrolysis Of

ABSTRACT A method for the chemical determination of 16-epi-oestriol in the urine of nonpregnant women with a qualitative sensitivity of less than 0.5 μg/24 h is described. The separation of 16-epi-oestriol and oestriol is accomplished by converting 16-epi-oestriol into its acetonide, a reaction which is stereoselective for cis-glycols and therefore not undergone by oestriol as a trans-glycol. Following partition between chloroform and aqueous alkali, the acetonide of 16-epi-oestriol is completely separated with the organic layer whereas oestriol as a strong phenol remains in the alkaline phase. 16-epi-oestriol is chromatographed on alumina as the acetonide and determined as a Kober chromogen. This procedure can easily be incorporated into the method of Brown et al. (1957 b) thus making possible the simultaneous routine assay of oestradiol-17β, oestrone, oestriol and 16-epi-oestriol from one sample of urine. The specificity of the method was established by separation of 16-epi-oestriol from nonpregnancy urine as the acetonide, hydrolysis of the acetonide by phosphoric acid, isolation of the free compound by microsublimation and identification by micro melting point, colour reactions and chromatography. The accuracy of the method is given by a mean recovery of 64% for pure crystalline 16-epi-oestriol when added to hydrolysed urine in 5–10 μg amounts. The precision is given by s = 0.24 μg/24 h. For the duplicate determination of 16-epi-oestriol the qualitative sensitivity is 0.44 μg/24 h, the maximum percentage error being ± 100% The quantitative sensitivity (±25% error) is 1.7 μg/24 h.

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