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1.
A micro chip element with an integrated flow channel and thin film thermopiles was developed in order to realize a micro calorimeter for small volumes in a flow arrangement. The flow channel consists of two inlets, a mixing region, a measurement region, and one outlet. Thermopiles of BiSb/Sb thermocouples were used as thermal transducers because of their extraordinary high thermopower. A thin film heater of a NiCr alloy was integrated in order to yield the possibility of internal electrical calibration. In addition, this heater can be used for thermal modulation of the whole measurement system. The calorimeter was prepared using vacuum evaporation, PECVD and magnetron sputtering for thin film deposition and photolithography as well as chemical wet etching for microstructuring. The function of the device was tested to neutralize 400 nmole, 100 nmole and 10 nmole NaOH by H2SO4.  相似文献   

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Wei Sun  Wenhua Li  Jing Li  Jian Zhang  Lupei Du  Minyong Li 《Tetrahedron》2012,68(27-28):5363-5367
Herein, we report the design and synthesis of two naphthalimide-based fluorescent probes. These probes provided high on/off signal ratios and exhibited good selectivity towards thiols over other analytes. Thus, they were identified as good sensors for the detection of thiols both in living cells and in rabbit plasma samples.  相似文献   

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Summary A simple field test for the detection of mercury is described. The test is based on the ligand exchange reaction where hexacyanoferrate(III) exchanges its cyanide ions with chromogenic organic ligand succinyl dihydroxamic acid (SDHA). In the reaction the colourless SDHA reacts with yellow K3Fe(CN)6 to give a greenish blue coloured complex in a slightly acidic solution containing mercury. The reaction has been successfully applied for the detection of mercury in polluted water, air and soil samples. In air, at a velocity of 0.21/min of the impinging air and a reaction temperature of 70°C, mercury(II) as low as 0.01 g could be easily detected after 3 min exposure. In water the limit of identification and limit of dilution were found to be 0.2 g Hg(II) and 1:200000, respectively.  相似文献   

5.
A micro-machined piezoresistive type tactile sensor (5mm x 6mm), composed of two zigzag structures which act as spring, with 500μm cubic contact mesas at their tips, has been fabricated for detecting compliance of soft tissue. The concept of applying two springs, with considerably different stiffnesses, to soft tissue for compliance detection has been chosen to get output reading independent of the applied pushing distance between the sensor and the tissue. The testing process is done by three ways; by subjecting the sensor to 1-specimen chips with known stiffness, 2-silicone rubber, 3-chicken organs; namely heart, liver and leg.  相似文献   

6.
Perrhenate is quantitatively extracted into methyl isobutyl ketone from aqueous solutions containing copper(II), azide and an excess of 2,2'-bipyridine. Measurement of the extracted copper either by spectrophotometry or by atomic absorption spectrometry, allows the determination of perrhenate in the ranges 16–40 μg ml−1 or 3–16 μg ml−1 in the final dilution, respectively. The procedure is highly selective, being applicable in the presence of a large concentration of molybdate and a considerable number of foreign ions. The extracted species corresponds to the formula CuN3(bipy)2 ReO4.  相似文献   

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Summary Organic compounds containing hydrogen, no matter what their kind, yield hydrogen sulfide when heated to 220–250° in molten sulfur. A micro method for detecting hydrogen in organic materials is based on this finding. The procedure can be accomplished within the bounds of spot test analysis.
Zusammenfassung Organische wasserstoffhaltige Verbindungen jeder Art spalten beim Erhitzen auf 220 bis 250° in Gegenwart geschmolzenen Schwefels Schwefelwasserstoff ab. Darauf läßt sich in der Arbeitsweise der Tüpfelanalyse ein Mikronachweis von Wasserstoff in organischen Verbindungen begründen.

Résumé Les composés organiques contenant de l'hydrogène donnent naissance à de l'hydrogène sulfuré, quelle que soit leur espèce, lorsqu'on les chauffe à la température de 220–250° dans le soufre fondu. Une microméthode permettant de déceler l'hydrogène dans les substances organiques est fondée sur cette observation. La technique peut être mise en uvre dans les limites de l'analyse par essais à la touche.
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8.
Schulte-Ladbeck R  Kolla P  Karst U 《The Analyst》2002,127(9):1152-1154
A rapid and simple field test for the detection of triacetone-triperoxide (TATP) and hexamethylenetriperoxidediamine (HMTD), two explosives which find significant illegal use, has been developed. Unknown samples are first treated with a catalase solution to remove hydrogen peroxide traces, in order to provide selectivity towards peroxide-based bleaching agents which are contained in commercial laundry detergents. Subsequently, the peroxide-based explosives are decomposed via UV irradiation, thus yielding hydrogen peroxide, which is determined by the horseradish peroxidase (POD) catalysed formation of the green radical cation of 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonate (ABTS). The limits of detection for this method are 8 x 10(-6) mol dm(-3) for TATP and 8 x 10(-7) mol dm(-3) for HMTD, respectively. As an option, p-hydroxyphenylacetic acid (pHPAA) may be used as peroxidase substrate, resulting in lower limits of detection (8 x 10(-7) mol dm(-3) for TATP and HMTD). The complete method uses a mobile setup to be applied under field conditions.  相似文献   

9.
《Talanta》1962,9(1):83-84
The detection of the ferrocene nucleus of various substituted ferrocenes by a colour reaction with cyanoferrateIII ion is reported.  相似文献   

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A spot test for the detection of mercaptans is based on the reaction with sodium nitroprusside in the presence of an anion-exchange resin in OH? form, to give a pink color on a resin bead surface.  相似文献   

13.
Qureshi SZ  Ahmad ST  Haque S 《Talanta》1990,37(7):763-765
A new simple, sensitive and selective test for the detection of microgram amounts of aliphatic amines with diphenylcarbazide-soaked Whatman No. 1 filter paper as the detection medium is described. A feature of the study is the observation that the reaction does not take place in solution in the absence of the filter paper.  相似文献   

14.
A test paper for high-selectivity detecting fluoride ion in natural aqueous environments without any spectroscopic instrumentation was achieved by using Ru-bipy based quinonehydrazone as a chromo- and fluorogenic hybrid chemosensor.  相似文献   

15.
A micro high performance liquid chromatography coupled with a resonance Raman detection system is described. For highly sensitive Raman detection, aliphatic amines were derivatized with dabsyl chloride (4-dimethylaminoazobenzene-4′-sulfonyl chloride). The derivatives were separated on an ODS micro column (0.5 mm i.d. × 145 mm PTFE tube). Chromatograms were obtained by measuring the intensity of Raman scattering at 1136 cm?1 with the 488.0 nm line of an Arion laser. The lower detection limit was 1.5 ng and the RSD of relative peak height (n = 9) was 5.9% at 11 ng of methylamine derivative. Moreover, by stopping the flow of the micro HPLC system at the retention time of the individual derivatives, it was possible to measure their resonance Raman spectra.  相似文献   

16.
Fuzzy inference approach was applied to select the control input for the precision water bath of the heat exchange calorimeter used at a non-air-conditioned laboratory. The thermal fluctuation of the bath water was necessary to be kept within a narrow range. The cooling water or coolant kept at a temperature lower than the set temperature was circulated in the bath. The deviation corresponding to the difference between the set temperature and the observed temperature was observed as the input signal. The output or control input to be given to the heather element in the water bath was calculated by the fuzzy modus. The output function was simplified by means of circulating the cooling water. The contribution of each membership function was changed according to the thermal progress of the observed temperature of the water. The whole system including the control programs was examined by a practical water bath, and fairly good results were obtained. Reasonable recoveries were also shown for external thermal disturbances given to the controlled system.
Zusammenfassung Zur Wahl des Regel-Inputs des Präzisionswasserbades für ein Wärmeaustauschkalorimeter in einem nicht klimatisierten Laboratorium wurde eine Unschärfeschlußnäherung angewendet. Die thermischen Schwankungen des Wassers im Wasserbad müssen in engen Grenzen gehalten werden. Das Kühlwasser oder Kühlmittel mit einer niedrigeren Temperatur als die eingestellte Temperatur wird im Bad zirkuliert. Die Abweichung durch die Differenz zwischen der eingestellten Temperatur und der gemessenen Temperatur wird als Input-Signal beobachtet. Der an das Heizelement im Wasserbad weiterzuleitende Output oder Regel-Input wird mittels des Unschärfe-Modus berechnet. Die Output-Funktion wird durch das Zirkulieren des Kühlwassers vereinfacht. Der Beitrag jeder Teilfunktion wird in Abhängigkeit vom thermischen Verlauf der gemessenen Wassertemperatur geändert. Einschließlich der Regelprogramme wurde das gesamte System an einem praktischen Wasserbad erprobt und man erhielt recht gute Ergebnisse. Akzeptable Diagnosen konnten auch für externe thermische Störeinflüsse gezeigt werden, denen das geregelte System ausgesetzt wurde.
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A flow-injection method for the determination of dissolved cobalt(II) in sea water has been studied based on a combination of column preconcentration using 8-quinolinol immobilized on silica gel, fluoride containing metal alkoxide glass (8HQ-MAF) and chemiluminescence detection with a gallic acid-hydrogen peroxide system. Co(II) is selectively recovered from an acidified sample with 8-quinolinol immobilized on silica gel. After elution with dilute hydrochloric acid the resultant eluent is mixed with the reagent solutions, heated to 60 ( degrees )C and then introduced into the CL cell. The analysis time including the 2-min sample load was 8 min per sea water sample with a corresponding detection limit of 0.62 ng l(-1) (3sigma). The average standard deviation calculated for 10 replicate measurements of artificial sea water samples with a concentration of 10 ng l(-1) cobalt was +/-2.1%. The method has been tested with the standard reference sea waters NASS and CASS.  相似文献   

19.
A flow-injection method for the determination of dissolved cobalt(II) in sea water has been studied based on a combination of column preconcentration using 8-quinolinol immobilized on silica gel, fluoride containing metal alkoxide glass (8HQ-MAF) and chemiluminescence detection with a gallic acid-hydrogen peroxide system. Co(II) is selectively recovered from an acidified sample with 8-quinolinol immobilized on silica gel. After elution with dilute hydrochloric acid the resultant eluent is mixed with the reagent solutions, heated to 60°C and then introduced into the CL cell. The analysis time including the 2-min sample load was 8 min per sea water sample with a corresponding detection limit of 0.62 ngl-1 (3). The average standard deviation calculated for 10 replicate measurements of artificial sea water samples with a concentration of 10 ngl-1 cobalt was ±2.1%. The method has been tested with the standard reference sea waters NASS and CASS.  相似文献   

20.
Automated preconcentration techniques for off/on-line determination with ICP-OES have been developed for various metal ions of environmental interest. Preconcentration studies were performed on two different types of chemically bonded chelating ion-exchangers, namely EDTrA-cellulose (iminoacetate groups) and HSO3 · oxine-cellulose. Enrichment studies were carried out at various preconcentration factors and also at different loadings.Presented in part at the 1989 European Winter Conference on Plasma Spectrochemistry, Reutte, Austria  相似文献   

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