Nachweisung von 1/1000 Milligram. Chinin

Ohne Zusammenfassung     

Volume calibration of 1000 μl micropipettes. Inter-laboratory comparison

A EUROMET comparison “volume calibration of 1000 μl micropipettes”, between six national metrology institutes (NMIs), was performed during 2006 with the purpose of comparing results and uncertainty calculations. The objective of this paper is to describe the volume measure instruments, the model, the method, and to discuss the results and its associated uncertainties presented by each participating NMI.     

Affinity chromatography of serine proteinases from the bovine intervertebral disc on BPTI-Separon HEMA 1000.

A method for the purification of serine proteinases from the bovine intervertebral disc using affinity chromatography on basic pancreatic trypsin inhibitor (BPTI) immobilized to the hydroxyalkyl methacrylate copolymer Separon HEMA 1000 E is reported. Its advantage is the possibility of obtaining serine proteinases without an artificial alteration in relative molecular mass.     

Heat capacity of indium from 300 to 1000 K

The heat capacity of high-purity indium has been determined by adiabatic-shield calorimetry in the range 300 to 1000 K. Values of thermodynamic functions have been calculated andC _p (1000 K), [H° (1000 K)–H° (298.15 K)], and [S° (1000 K)–S° (298.15 K)] are (27.11±0.15) J K^–1 mole^–1, (22873±70) J mole^–1, and (41.567 ±0.125) J K^–1 mole^–1, respectively. The enthalpy of fusion is (3283±7) J mole^–1 and the melting temperature (429.77±0.01) K. The premelting heat capacity is compatible with the presence of a mole fractionx 1·10^–6 of a liquid-soluble/solidinsoluble impurity in the sample.

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Zusammenfassung Die Wärmekapazität von hochreinem Indium wurde im Bereich von 300 bis 1000 K durch adiabatische Schildkalorimetrie bestimmt. Die Berechnungen der thermodynamischen Funktionen:C _p (1000 K), [H° (1000 K)–H° (298.15 K)] und [S° (1000 K–S° (298.15 K)] ergab 27.11±0.15 J K^–1 Mol^–1, (22 875±70) J Mol^–1, bzw. (41.567±0.125) J K^–1 Mol^–1. Die Schmelzenthalpie beträgt (3283±7) J Mol^–1 und die Schmelztemperatur (429.77±0.01) K. Die Vorschmelz-Wärmekapazität ist mit der Gegenwart einer Molfraktionx1×10^–6 einer flüssig-löslich/fest-unlöslichen Verunreinigung in der Probe vereinbar.

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Résumé La chaleur spécifique de l'indium de haute pureté a été déterminée entre 300 et 1000 K par calorimétrie adiabatique. Les valeurs des fonctions thermodynamiques suivantes ont été calculées:C _p (1000 K)=(27.11±0.15) J K^–1mol^–1, [H° (1000 K)–H° (298.15 K)]= (22 875±70) J mol^–1 et [S° (1000 K)–S° (298.15 K)]=(41.567±0.125) J K^–1 mol^–1. L'enthalpie de fusion est (3283±7) J mol^–1 et la température de fusion (429.77±0.01) K. La chaleur spécifique de pré-fusion est compatible avec la présence d'une fraction molairex1×10^–6 d'une impureté dans l'échantillon, soluble dans le liquide, insoluble dans le solide.

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C - 300 1000 . : _p(1000 ), [ (1000 ) — H (298,15 )] [S (1000 ) — S (298.15 )], : 27.11±0.15 . ^–1. ^–1, 2 2875±70 . ^–1 41.567±0.125 . ^{– 1–1}. 3283±7 .^–1, – 429.77±0,01 . - / 1.10^–6.

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The assistance of Bjørn Lyng Nielsen with the experimental work is recognized with thanks.     

Heat capacity of gold from 80 to 1000 K

The heat capacity of gold has been measured by laserflash calorimetry in the temperature range 80–1000 K. The results are compared with available low- and high-temperature heat capacities, and revised thermodynamic values of gold are given.     

MIXED MICELLES OF CATIONIC SURFACTANTS IN AQUEOUS POLYETHYLENE GLYCOL 1000

The conductances of tetradecyltrimethylammonium bromide (TTAB) + dodecyltrimethylammonium bromide (DTAB) mixtures over the entire mole fraction range of TTAB (^αOITTAB) were measured in aqueous polyethylene glycol 1000 (PEG) containing 1, 2, 5 and 10 wt% of PEG at 30 °C. From the conductivity data, various micellar parameters were computed. The results have been explained on the basis of the medium effects as well as the adsorption of additive molecules at micelle-solution interface. The non-ideality in TTAB+DTAB mixtures was evaluated by using the regular solution theory and Motomura's formulation based on the excess thermodynamic quantities. It has been found that the regular solution interaction parameter (β) and micellar mole fraction (¯x ^m ₂) remain almost unaffected even in the presence of upto 10 wt% of PEG. These results suggest that the additive remains only in the aqueous phase and perhaps only changing the environment surrounding the micelles by adsorbing at the micelle-solution interface.     

Thermal dissociation of SO3 at 1000-1400 K

The thermal dissociation of SO3 has been studied for the first time in the 1000-1400 K range. The experiments were conducted in a laminar flow reactor at atmospheric pressure, with nitrogen as the bath gas. On the basis of the flow reactor data, a rate constant for SO3 + N2 --> SO2 + O + N2 (R1b) of 5.7 x 10(17) exp(-40000/T) cm3/(mol s) is derived for the temperature range 1273-1348 K. The estimated uncertainty is a factor of 2. The rate constant corresponds to a value of the reverse reaction of k1 approximately 1.8 x 10(15) cm6 mol(-2) s(-1). The reaction is in the fall-off region under the investigated conditions. The temperature and pressure dependence of SO2 + O (+N2) was estimated from the extrapolation of low temperature results for the reaction, together with an estimated broadening parameter and the high-pressure limit determined recently by Naidoo, Goumri, and Marshall (Proc. Combust. Inst. 2005, 30, 1219-1225). The theoretical rate constant is in good agreement with the experimental results. The improved accuracy in k(1) allows a reassessment of the rate constant for SO3 + O --> SO2 + O2 (R2) based on the data of Smith, Tseregounis, and Wang (Int. J. Chem. Kinet. 1982, 14, 679-697), who conducted experiments on a low-pressure CO/O2/Ar flame doped with SO2. At the location in the flame where the net SO3 formation rate is zero, k2 = k1[SO2][M]/[SO3]. A value of 6.9 x 10(10) cm3 mol(-1) s(-1) is obtained for k2 at 1269 K with an uncertainty a factor of 3. A recommended rate constant k2 = 7.8 x 10(11) exp(-3065/T) cm3 mol(-1) s(-1) is consistent with other flame results as well as the present flow reactor data.     

Thermally reversible pluronic/heparin nanocapsules exhibiting 1000-fold volume transition

Novel Pluronic/heparin composite nanocapsules that exhibit a thermally responsible swelling and deswelling behavior were synthesized. Pluronic F-127 preactivated with p-nitrophenyl chloroformate at its two terminal hydroxyl groups was dissolved in a methylene chloride phase. The organic phase was dispersed in an aqueous phase containing heparin. At an organic/aqueous interface, Pluronic-cross-linked heparin nanocapsules were produced. They exhibited a 1000-fold volume transition (ca. 336 nm at 25 degrees C; ca. 32 nm at 37 degrees C), and a reversible swelling and deswelling behavior when the temperature was cycled between 20 and 37 degrees C. The reversible volume transition of Pluronic nanocapsules was caused by micellization and demicellization of cross-linked Pluronic polymer chains within the nanocapsule structure in response to temperature. The morphological characters were investigated with transmission electron microscopy and small angle neutron scattering. Pluronic/heparin nanocapsules had an aqueous fluid-filled hollow interior with a surrounding shell layer below the critical temperature, but they became a collapsed core/shell structure similar to that of Pluronic micelles above it.     

Convenient Synthesis of Monosubstituted Arylferrocenes Using PEG-1000 as Phase-Transfer Catalyst

A new approach for the synthesis of monosubstituted arylferrocenes based on the coupling of aryldiazonium salts with ferrocene using PEG-1000 as an efficient phase-transfer catalyst was developed. The present method is applicable to many kinds of substituted aromatic amines, providing good to excellent yields of desired products.