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JPC - Journal of Planar Chromatography - Modern TLC
Authors:
Mihaela Vlassa
,
Virginia Coman
,
Miuţa Filip
,
Florina Copaciu
,
Aurora Mocanu
, and
Maria Tomoaia-Cotişel

The basic of all proteins is constituted by approximately 20 common amino acids that differ only in the structure of their side chain. The purpose of our work was to use the overpressured layer chromatography (OPLC) technique for the separation and identification of the essential and non-essential amino acids from some most common proteins, like hen egg yolk protein, bovine serum albumin (BSA), and Type I Collagen from bovine achilles tendon. In this order, the target proteins were acid-hydrolyzed and derivatized. For the separation of essential amino acids from egg yolk, two successive OPLC developments (normal and overrunning) were performed, followed by direct derivatization with 4-hydroxybenzaldehyde and ninhydrin on the chromatoplate for identification. In the hydrolyzed egg yolk, nine essential amino acids were identified. Between lysine and histidine, a poor separation was obtained. The amino acids from BSA and Type I Collagen were separated and identified as phenylthiohydantoin (PTH) derivatives by OPLC. The supposed identity of the amino acids as PTH derivatives was confirmed by reversed-phase high-performance liquid chromatography (RP-HPLC). Seven essential amino acids (arginine, histidine, threonine, valine, methionine, isoleucine, and leucine) were found in bovine serum albumin (BSA), and six (histidine, threonine, valine, methionine, leucine, and lysine) in Type I Collagen. The same eight non-essential amino acids (cysteine, asparagine, glutamine, glycine, alanine, serine, tyrosine, and proline) were identified in these two proteins. By RP-HPLC, other two non-essential amino acids (aspartic acid and glutamic acid) were found both BSA and Type I Collagen. Cysteic acid was also found in BSA. In our samples, tryptophan was missing due to its destruction during hydrolysis.

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Abstract  

This paper extends past computer solutions for confidence intervals in paired counting. The net count is transformed to an integer; the resultant probability distribution is identical with that for detection limits when the blank is counted an integer number of times greater than the sample. Summation of the left tail of this distribution is used to determine left-hand and right-hand confidence limits with specified confidence levels for a given observed net count and known expected blank count in the sample count time. Poisson statistics are used throughout this paper and the Gaussian distribution is reserved for approximate results.

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Abstract  

This paper extends previous work for decision levels to detection limits. After transforming the net count to an integer, the probability density function for the transformed net count can be readily determined when the transformed net count is greater than zero. The right tail of the distribution is summed and the detection limit is determined to four decimal places. The code under discussion works well when the product of the ratio of the blank count time to the sample count time with the expected blank count in the sample count time is not greater than 100.0.

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Journal of Thermal Analysis and Calorimetry
Authors:
Tingting Fang
,
Xi Li
,
Chenggang Wang
,
Zhijun Zhang
,
Tian Zhang
,
Junmin Zeng
,
Peng Liu
, and
Chaocan Zhang

complexes intercalated in γ-zirconium phosphate . J Therm Anal Calorim 97 : 805 – 810 10.1007/s10973-009-0225-y . 20. D'Aurora , V , Stern , AM , Sigman , DS 1977 Inhibition of DNA

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MP Biomedicals Inc. (95%, Aurora, OH, Germany). They were used without further purification. All organic solvents were of analytical grade. Double deionized water with a resistivity of about 18.2 MΩ·cm was used for the preparation of buffers

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Acta Chromatographica
Authors:
Waqar Siddique
,
Rai Muhammad Sarfraz
,
Muhammad Zaman
,
Riffat Khan
,
Maria Gul
,
Farhan Asghar
,
Tangina Malik
,
Asiya Saif
,
Qurat-Ul-Ain Shamim
,
Ahmad Salawi
,
Meshal Alshamrani
,
Yosif Almoshari
, and
Fahad Y. Sabei

, C. ; Nappi , G. Eletriptan. Expert Opin Drug Metab Toxicol. 2009 , 5 ( 12 ), 1587 – 1598 . 18. Aurora , S.K. ; Papapetropoulos , S. ; Kori , S.H. ; Kedar , A. ; Abell , T.L. Gastric stasis in migraineurs: etiology, characteristics

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