Picric Acid Method for Determination of Aromatic Content of Aviation Gasoline

1946 ◽  
Vol 18 (11) ◽  
pp. 689-692 ◽  
Author(s):  
C.M. Gambrill ◽  
J.B. Martin
Keyword(s):  
Picric Acid ◽  
Aviation Gasoline ◽  
Aromatic Content ◽  
Acid Method

Determination of Guanidines in Rubber Stocks and Consumption of Guanidines during Cure

1936 ◽  
Vol 9 (4) ◽  
pp. 661-670
Author(s):  
Bingham J. Humphrey
Keyword(s):  
Organic Material ◽  
Picric Acid ◽  
Effective Procedure ◽  
Considerable Difficulty ◽  
Vulcanized Rubber ◽  
Acid Method ◽  
Copper Oleate ◽  
Reliable Methods

Abstract QUANTITATIVE determinations of various accelerators that may be present in vulcanized rubber stocks are necessary, not only for fundamental investigations into the mechanism of acceleration, but also for routine control analyses and the examination of unknown stocks. The determination of any organic material in vulcanized rubber stocks is beset with numerous difficulties, however, and reliable methods are scarce. For accelerators, the only ones described in the literature are the now generally employed copper oleate method for mercaptobenzothiazole and an extension of Callan and Strafford's (1) picric acid method for guanidines, both described by Wistinghausen (2). Using these two procedures, Wistinghausen made an extended investigation of the consumption of mercaptobenzothiazole and of diphenylguanidine (D. P. G.) during cure. Considerable difficulty was encountered in this laboratory in the use of Wistinghausen's method. Especially with di-o-tolylguanidine (D. O. T. G.) stocks, the results were highly variable and the proportion of guanidine recovered seemed to be much smaller than that recovered by Wistinghausen from similar stocks. As a test of both the method and the technic, an uncured di-o-tolylguanidine tread stock was analyzed, since it was believed that, in this case, an effective procedure should account for substantially all of the guanidine put into the stock. The result was that little or no more guanidine was recovered from the uncured stock than from the same stock at an optimum cure. Guanidine recoveries from either one ranged from 30 to 50 per cent.

Comparison of several methods for semiquantitative determination of urinary protein.

1977 ◽  
Vol 23 (5) ◽  
pp. 876-879 ◽  
Author(s):  
W L Gyure
Keyword(s):  
Serum Albumin ◽  
Salt Concentration ◽  
Urine Samples ◽  
Urine Protein ◽  
Sulfosalicylic Acid ◽  
Green Method ◽  
Semiquantitative Determination ◽  
Acid Method ◽  
Bromcresol Green

Abstract Two types of urine protein dipsticks and the sulfosalicylic acid method were compared for their accuracy and specificity, with use of urine samples supplemented with various proteins. Dipsticks yield accurate results when the protein under consideration is restricted to albumin; the sulfosalicylic acid method accurately determines many kinds of proteins in addition to albumin. Detergents affect each of the methods, but changes in salt concentration only affect results by dipstick procedures. Dipsticks, which are based on the protein-error principle for indicators, are subject to some of the conditions that apply to the bromcresol green method for serum albumin determination.

Strongly fluorescent cysteamine-coated copper nanoclusters as a fluorescent probe for determination of picric acid

2018 ◽  
Vol 185 (11) ◽  
Author(s):  
Zhijun Bao ◽  
Kui Zhang ◽  
Jingyi Jian ◽  
Ziwei Hu ◽  
Kaisong Yuan ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Picric Acid ◽  
Copper Nanoclusters
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