Cross-Contaminator Exclusion Test for Dry-Ashing Determination of Protein-Bound Iodine

1955 ◽  
Vol 1 (4) ◽  
pp. 269-272 ◽  
Author(s):  
Mayer Samson ◽  
Herman Brown ◽  
Seymour Eichen

Abstract A simple qualitative test for iodine in blood serum has been described. It is designed to detect sera which are potential cross-contaminators in dry-ashing PBI procedures. One drop of serum is used. Added operating time in a PBI series of 20-40 determinations is not over 30 minutes.

2018 ◽  
Vol 1 (1) ◽  
pp. 58-66
Author(s):  
Novena Yety Lindawati

Taro is plant that has a pseudostalk,cylindrical and light brown bulbs. The shape of leaf is the heart in length. Leaf stalk of taro contains are saponins, flavonoids, tanins, alkaloids, steroids and terpenoids. Leaf stalk of taro can be used as an alternative medicines wound and antioxidants. Flavonoids have an important role in the biological activity of taro leaf stalk. This research aims to determine the flavonoid and total flavonoids content in the taro leaf stalk extract. The extraction is done using maceration method with 70% ethanolas solvent. The extract which is got is used for qualitative and quantitative analysis. Quercetin used as a standard solution. Quantitative analysis using UV-Vis Spectrophotometry on a wavelength of 435.5 nm and operating time at the 29th minute. The results of qualitative test showed that the extract was positive flavonoids. The average concentrations of total flavonoids was 10,2223mg QE/gram extract with %CV value of 0,3051%.


Author(s):  
Yu. P. Morozov

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.


1980 ◽  
Vol 45 (4) ◽  
pp. 1099-1108 ◽  
Author(s):  
Mikuláš Chavko ◽  
Michal Bartík ◽  
Evžen Kasafírek

A polarographic study of the hydrolysis of [8-lysine]vasopressin and some hormonogens of the vasopressin series with the blood serum of women in the last week of pregnancy was studied. The dependence of hydrolysis on pH (pH optimum: 7.4-7.50, substrate concentration (Km 1.2 . 10-5M), pH stability and thermal stability were determined. The rate of hydrolysis of individual vasopressin analogues decreases in the order: [8-lysine]vasopressin > Nα-glycyl-prolyl[8-lysine]-vasopressin > Nα-leucyl-[8-lysine]vasopressin > Nα-alanyl-[8-lysine]vasopressin > Nα-phenyl alanyl-[8-lysine]vasopressin > Nα-diglycyl-[8-lysine]vasopressin > Nα-prolyl-[8-lysine]vasopressin > Nα-triglycyl-[8-lysine]vasopressin > Nα-sarcosyl-glycyl-[8-lysine]vasopressin. The degree of hydrolysis gradually increases to a multiple with the length of the pregnancy in consequence of the presence of oxytocine. However, vasopressin is also hydrolysed to a small extent with the enzymes from the blood sera of non-pregnant women. Under similar analytical conditions oxytocin was not hydrolysed with the sera of non-pregnant women and therefore oxytocin is a more suitable substrate than vasopressin for polarographic determination of serum oxytocinase.


1930 ◽  
Vol 87 (1) ◽  
pp. 27-32
Author(s):  
F.H.L. Taylor
Keyword(s):  

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