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1.
Zusammenfassung Pentachlorphenol (PCP) wurde im Plasma und Harn mittels Capillar-Gas-Chromatographie und ECD-Detektion erfaßt. Die parallele Analyse mit einem massenselektiven Detektor erbrachte nahezu identische Werte (r=0,9978). Die Nachweisgrenzen lagen bei ca. 5 g PCP/l Harn bzw. ca. 10 g PCP/l Plasma. Die Untersuchung von 27 Personen ohne beruflichen bzw. besonderen usuellen Kontakt mit Pentachlorphenol ergab mediane PCP-Konzentrationen im Plasma von 28 g/l (95.0 Perzentil 149 g/l) bzw. im Harn von 10 g/l (95.0 Perzentil 55 g/l).
Determination of pentachlorophenol in human plasma and urine samples by capillary gas chromatography with ECD- and MS-detection
Summary Pentachlorophenol (PCP) levels in plasma and urine samples were determined by capillary gaschromatography and EC-detection. The results of the parallel analysis of samples with a selective mass detector correlated well (r=0.9978). The detection limits were around 5 g PCP/l urine and around 10 g PCP/l plasma respectively. A study on 27 persons occupationally not exposed to PCP or without a known special ecological intake of PCP showed median PCP levels of 28 g/l plasma (95.0 percentile: 149 g/l plasma) and 10 g/l urine (95.0 percentile: 55 g/l).
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2.
Zusammenfassung Ziel der Arbeit war die Entwicklung einer Schnellmethode zur Bestimmung des Wassergehaltes von in der Gummiindustrie als Füll- und Verfestigungsstoffe angewandten Silikaten. Da diese das Wasser teils adsorptiv, teils chemisch gebunden enthalten, wurde durch IR-Untersuchungen verfolgt, wie sich bei unterschiedlichen Bedingungen die Art der Bindung des Wassers verändert. Das physikalisch gebundene Wasser wurde thermometrisch bestimmt. Diese Methode beruht darauf, dass die Wärmetönung der Reaktion zwischen Karl-Fischer-Lösung und Wasser stark exotherm ist und im adiabatischen Kalorimeter die Temperaturveränderung unter geeigneten Bedingungen proportional dem Wassergehalt ist.
The aim of the present work was to develop a rapid method for moisture determination in silicic acid used in rubber industry as a reinforcer and ingredient. Water is bound in silicic acid by chemical and adsorption forces. The changes in the nature of the bond under different conditions were studied by infrared spectroscopy.The amount of the physically bound water was determined by direct thermometry (DIE). The method is based on the phenomenon that the heat of reaction between the Karl Fischer reagent and water is great, and that in an adiabatic calorimeter under appropriate conditions the temperature change is proportional to the water content of the samples.

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3.
The interference contributions of uranium and thorium to the determination of cerium based on radionuclides141Ce and143Ce produced by irradiation in a reactor core was determined. The values of the interference contributions for141Ce were 0.28±0.01 g Ce/g U and /2.01±0.05/x10–3 g Ce/g Th, and for143Ce 1.33±0.03 g Ce/g U and /9.0±0.2/x10–3 g Ce/g Th.  相似文献   

4.
The microwave spectrum of 1,3dioxolane (C3H6O2) in the ground and first three excited states of hindered pseudorotation was studied. The transitions corresponding to the b, c, and a components of the dipole moment were identified. The spectrum was analyzed using numerical diagonalization of the effective rotational Hamiltonian for four interacting states of hindered pseudorotation. The rotational constants, centrifugal distortion constants, the constants of interaction between general rotation and hindered pseudorotation, and the distances between the quasidegenerate vibrational levels 01 = 64840.5, 12 = 122231.7 and 23 = 119732.7 MHz are determined. From the Stark effect of microwave transitions, the dipole moment components (in Debye units) in the hinderedpseudorotation states v = 0, 1, 2, and 3 are determined: 0|b|0 = 1|b|1 = 1.22, 2|b|2 = 1.20, 3|b|3 = 1.21, 0|c|1 = 0.77, 2|c3 = 0.66, and 1|a|2 = 0.19.  相似文献   

5.
Schemes of redox transformations were proposed for osmium carbonylhydride clusters: trinuclear (-H)Os3(-CR = CHR')(CO)1 0 (R = R' = H, Ph; R = H, R' = Ph), (-H)2Os3(3-L)(CO)9 (L = C = CHPh, CHCPh), tetranuclear CpMnOs3 (-CH = CHPh)(-H)(-CO)(CO)1 1, and trinuclear Os3(3-C = CHPh)(CO)9. Two-electron reduction of the trinuclear clusters results in elimination of the unsaturated ligand with preservation of the metal framework.  相似文献   

6.
Xu  Feng  Sun  Wen-Hua  Yang  Shi-Yan  Yin  Yan-Qi  Wu  Qin-Jin  Yu  Kai-Bei 《Transition Metal Chemistry》1997,22(2):176-179
HFe2Co(CO)9(3-S) reacts with (5-Cp)Mo(CO)3Cl in refluxing THF to give heterometallic trinuclear clusters (5-Cp)MoFeCo(CO)8(3-S) and [(5-Cp)Mo]2Fe(CO)7-(3-S), which have been characterized by elemental analyses, i.r., 1H- and 13C-n.m.r. and X-ray crystal structure determination. An electrophilic addition–elimination sequence is proposed for their formation.  相似文献   

7.
Reaction of Ru4(CO)13(3-PPh) (1) with the 1,3,5-hexatriyne Me3SiCCCCC CSiMe3 under mild thermal conditions affords initially Ru4(CO)10(-CO)2{4-1,1,2-P(Ph)C(CCSiMe3)C(CCSiMe3) (2), via the facile formation of a P–C bond in a manner similar to that demonstrated previously with alkynes and diynes. The 62-CVE cluster 2 readily decarbonylates to give crystallographically characterised Ru4(CO)10(-CO)(4-PPh){4-1,1,2,2-Me3SiCCC2CCSiMe3} (3). Attempts to further incorporate the pendant alkyne moieties in 3 into the Ru4 coordination environment were partially successful with Ru4(CO)10(4-PPh)(4-1,1,3,3-RC4R') (4, R/R'=SiMe3/CCSiMe3) being formed as a minor product together with the unusual toluene coordinated species Ru4(CO)7(6-C6H5Me)(4-PPh)(4-1,1,3,3-Me3SiC4CCSiMe4) (5). Cluster 3 reacts with an excess of Me3SiCCCCCCSiMe3 to give the open chain cluster Ru4(CO)9(3-PPh){4-2,2,4,4,-C4(CCSiMe3)(SiMe3)C4(CCSiMe3)3} (6).  相似文献   

8.
A procedure was developed for the gas-chromatographic determination of promedol (trimeperidine) and ketamine in whole blood with mass-selective detection. The detection limit for trimeperidine and ketamine in blood is 0.05 g/mL. The analytical range is 0.1–5.0 g/mL. The maximum within-series errors in the determination of the studied compounds are no higher than 14.1% for concentrations of 0.10 g/mL and 7.47% for concentrations of 1.0 g/mL. The maximum between-series relative errors are 5.75% for concentrations of 0.10 g/mL and 2.7% for concentrations of 1.0 g/mL. The procedure can be used in toxicological and clinical analyses.  相似文献   

9.
Zusammenfassung Eine neue Methode zur Durchführung gravimetrischer Bestimmungen im Mikrogrammbereich wurde beschrieben; diese beruht im wesentlichen darauf, daß der Niederschlag nicht mehr zusammen mit dem Filter, sondern nach Überführen mit einem geeigneten Lösungsmittel in einem separaten Wägegefäß gewogen wird.Die dazu nötigen Geräte und deren Herstellung wurden beschrieben. Nach dieser Methode wurden folgende Bestimmungen mit zufriedenstellender Richtigkeit durchgeführt: 2,5–25g Al, 5–50g Cu und 5–50g Zn mit Oxin, 2,5–25g Fe(III) und 2,5–25g Ti(IV) mit N-Benzoyl-phenylhydroxylamin, 5–50g Ni und 5–50g Cu mit Salicylaldoxim, 2,5–50g Co(II) und 2,5–50g Fe(III) mit -Nitroso--naphthol sowie 5–50g Chlorid als Silberchlorid.
Precipitation analysis in the microgram-scale: A new method
Summary A new method for gravimetric determinations in the microgram-scale is described. This method is based on the fact that the precipitate is not weighed together with the filter but is transferred to a separate weighingvessel using a suitable solvent. The necessary simple devices and their use are described. The following determinations were carried out with satisfying accuracy: 2,5–25g Al, 5–50g Cu and 5–50g Zn with Oxine, 2,5–25g Fe and 2,5–25g Ti withN-benzoylphenylhydroxylamine, 5–50g Ni and 5–50g Cu with salicylaldoxime, 2,52–50g Co and 2,5–50g Fe with -nitroso--naphthol and 5–50g chloride as silver chloride.
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10.
Starting with the trinuclear clusters, M3(CO)12 (where M=Os or Ru), Os3(CO)11(NCCH3), Os3(CO)10(NCCH3)2, and (-H)Os3(-OR)(CO)10 (where R=H or Ph), and polyfunctional organic compounds containing vinyl or allyl groups, a number of cluster monomeric complexes have been synthesized containing ligands with an uncoordinated C=C bond,viz.: (-H)Os3(-4-Vpy)(CO)10, (-H)Os3(-O2CCH=CH2)(CO)10, (-H)Os3(-OCNHCH2CH=CH2)(CO)10, and (-H)M3(-SCH2CH=CH2)(CO)10. The (-H)Os3(-4-Vpy)(PPh3)(CO)9 complex was investigated by X-ray diffraction analysis.For part 30, seeRuss. Chem. Bull., 1993,42, 1016.Vpy is the vinylpyridine ligand.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1293–1298, July, 1993.  相似文献   

11.
Summary A simple and fast determination of trace amounts of commercially used cationic surfactants is described. After extraction from water cationic surfactants are separated by HPLC and detected by conductometry. The detection limit is 3 g/l for distearyldimethylammonium chloride, 16 g/l for ditallowimidazolinium methosulphate, and 6 g/l for dodecylpyridinium chloride.  相似文献   

12.
Acetonation of L-sorbose—a step of ascorbic acid synthesis—takes place in acetone to yield 85% of diacetone-L-sorbose in the presence of heteropoly acids H3PW12O40 and H4SiW12O40 (0.1–0.35%) as catalysts.
L-— L- — -L- 85% 0.1–0.35% H3PW12O40 H4SiW12O40 .
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13.
    
A computer-controlled flow injection system was developed for the determination of cadmium in a hydrometallurgical zinc refining process stream. An anion-exchange method in acidic potassium iodide medium was used for the on-line separation of cadmium from the matrix zinc. 1-(4-Nitrophenyl)-3-(4-phenylazophenyl)triazene (Cadion) was used as the chromogenic reagent for the spectrophotometric detection of cadmium. In order to expand the dynamic range of the flow injection - spectrophotometry, a computer-aided time-based variable-volume injection method has been employed for the introduction of the sample into the flow injection system. Samples ranging from 0.56 to 350 l can be delivered by controlling the time period of the sample introduction valve and the flow rate of the carrier solution. The system permits a throughput of 5 samples per hour. The reproducibility has been proven to be satisfactory with a relative standard deviation of less than 6.2% (sample injected: 0.56 l of 850 g Cd/ml; n=100) and 5.0% (350 l of 0.14 g Cd/ml; n=5). The determination limit was 20 g Cd/ml with 0.56 l sample injection and 0.05 g Cd/ml with 350 l sample injection (the absolute amount of cadmium injected into the system was 11 ng and 17.5 ng, respectively).  相似文献   

14.
The capillary rise of liquids was investigated in square capillary tubings of different dimensions (e. g. 300 m · 300 m to 1000 m · 1000 m) in the temperature range 25° to 35°C.The data were fitted to an equation:=1/2 · ·g · (S · (C ·H/2 +C ·S)) where is the surface tension of the liquid,S is the side length of the square tubing,H is the capillary rise,C (= 1.089) is a capillary constant.  相似文献   

15.
A method for the determination of aldrin, dieldrin, DDT, DDE, and DDD contamination in animal fats (beef tallow, lard, and chicken fat) without using toxic reagents is developed, that uses high-performance liquid chromatography after the sample has been prepared by matrix solid-phase dispersion (MSPD) with acidic alumina oxide. A reversed-phase C1-silica column with a mobile phase of 50% (v/v) ethanol solution (in water) and a photo-diode array detector were used for the determination. Average recoveries of the target compounds (0.2–5.0 g g–1) ranged from 84–98%, with coefficients of variation of <5%. The limits of quantitation were 0.16 g g–1 for AD, 0.10 g g–1 for DD, 0.06 g g–1 for DDT, 0.07 g g–1 for DDE, and 0.05 g g–1 for DDD. No toxic reagents were used at all.  相似文献   

16.
Binuclear and trinuclear transition-metal -allenyl complexes—especially mixedmetal complexes—are reviewed. In recent years, a number of such compounds have been prepared by use of several synthetic methods. The most general of these methods, viz. reactions of metal propargyls and of the lower nuclearity metal allenyls with low-valent metal complexes such as metal carbonyls and platinum(0) compounds, are considered in some detail. The structures of the binuclear metal -1,2- and -3,2-allenyl complexes and of the trinuclear metal 3-1,2,2-allenyl complexes—both triangular and open—are presented and compared. Trends in the1H and13C NMR spectroscopic properties of these compounds are examined. Some aspects of reaction chemistry of the heteronuclear platinum-ruthenium -1,2-allenyl complexes are presented.  相似文献   

17.
Zusammenfassung Es wird eine photometrische Bestimmungsmethode beschrieben für Anilin (40–720 g/ml), Monoäthylanilin (90–1650 g/ml) und Diäthylanilin (100–1600 g/ml) mit Natriumchlorit in äthanolisch-wäßrigen Lösungen, sowie für Diäthylanilin (85–1140 g/ml) und Dimethylanilin (30–330 g/ml) neben den primären und sekundären Aminen in essigsaurer Lösung mit demselben Reagens. Das Verfahren liefert gute Ergebnisse.
Summary A photometric procedure is described for the determination of aniline (40–720 g/ml), monoethylaniline (90–1650 g/ml), and diethylaniline (100–1600 g/ml) with sodium chlorite in aqueous ethanolic solutions and of diethylaniline (85–1140 g/ml) and dimethylamline (30 to 330 g/ml) in presence of the primary and secondary amines in acetic acid solution using the same reagent. Good results have been obtained,
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18.
Summary Solochrome Black 6 BN in an acetate buffered medium containing methanol reacts with U(IV) to give a blue complex which permits photometric determination with 5g U/ml to 100g U/ml.In the presence of zinc acetate, uranyl ion also may be spectrophotometrically determined by means of the same dye. From 2g U/ml to 40g U/ml may be determined with a relative error of less than ± 0.05.
Zusammenfassung Es werden zwei Methoden zur spektrophotometrischen Bestimmung von Uran mittels Solochromschwarz 6 BN beschrieben. Dieser Farbstoff bildet mit U(IV) in acetatgepuffertem, methanolhältigem Medium einen blaugefärbten Komplex, der die Bestimmung von 5 bis 100g U/ml erlaubt.Mit demselben Farbstoff lassen sich auch 2 bis 40g U/ml in Lösungen von Uranylchlorid bestimmen.

Résumé Le noir solochrome 6 BN en milieu tampon acétique contenant du méthanol réagit avec U-IV en donnant un complexe bleu qui permet le dosage photométrique de 5 g U/ml à 100 g U/ml.En présence d'acétate de zinc, on peut aussi doser l'ion uranyle par spectrophotométrie avec le même colorant. On peut doser de 2 g U/ml à 40 g U/ml avec une erreur relative inférieure à ± 0,05.
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19.
Analyses of rainwater are routinely performed by a number of organisations to monitor the contribution from rainwater to the component occurrences in the environment and the acidification of the environment. To control the quality of such determinations, the Community Bureau of Reference (BCR) has organised a certification campaign to produce two simulated rainwater reference materials (CRM 408, low mineral content and CRM 409, high mineral content). The materials were carefully prepared (addition of pro analysis and supra pure reagents with the mentioned elements to silica-free deionised water) and its homogeneity and long-term stability were verified. The materials were certified for their contents of ammonium (106 mol/kg) (CRM 409), calcium (7.68 and 15.5 mol/kg), chloride (67.3 and 113 mol/kg), hydronium (16.6 and 48.0 mol/kg), magnesium (6.14 and 12.3 mol/kg), nitrate (20.1 and 78.1 mol/kg), potassium (4.25 mol/kg) (CRM 409), sodium (42.0 and 82.9 mol/kg) and sulphate (10.5 and 53.2 mol/kg). Indicative values (not certified) are given for ammonium and potassium in CRM 408. This paper presents the certification work performed, as well as the analytical work for the certification of the contents of relevant species.  相似文献   

20.
The trace metal loading of used car and truck tires and the fractions of the metals volatilized upon incineration of the tire were determined. INAA was chosen due to its multielement analysis capability and its low detection limit for many elements. A high purity planar germanium detector was used. Among the elements measured were, Al (4–150 g/g), Ti (41–730 g/g), V (0.04–0.4g/g), Mg (>80–580 g/g), Zn (1–2.2%) as typical concentrations; also some amounts of antimony, bromine and arsenic have been found. Major differences in elemental concentrations have been observed between the tread and the wall of a tire, and also between different brands.  相似文献   

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