Comparison of costs for testing a wide variety of drugs of abuse per urine specimen in a drug abuse urine screening program and frequent urine collections.

Existing urine testing techniques in a drug abuse urine screening program with their capacity to analyze urine specimens per day are discussed. The start-up cost using each technique and cost per specimen are presented. A single step extraction technique using ion-exchange paper to absorb drugs prior to thin-layer chromatography (TLC) as reported by these laboratories will cost $0.58 per specimen, for testing the entire aray of drugs of abuse (at least 9-14 tests per specimen). Sensitivity reported using TLC technique for the morphine base is 0.15 mug/ml (minimum volume of urine needed 20 ml), 0.10 mug/ml if the volume of urine available is 30-35 ml, and 0.07 mug/ml if the volume of urine available is 43-50 ml.     

I fondamenti chimici e chimico-fisici della microdeterminazione colorimetrica dell'acido fosforico mediante l'azzurro di molibdeno

Résumé Après une énumération brève des méthodes principales pour la détermination de l'acide phosphorique dans une matière biologique, on a conclu, que la méthode colorimétrique pour la détermination du bleu de molybdène est la méthode la plus digne de confiance pour la détermination de l'acide phosphorique.On discute les bases théoriques de cette méthode et les conditions chimiques et physico-chimiques dont l'accomplissement est nécessaire pour atteindre des dosages précises. Aussi on met en ligne de compte l'application de cette méthode sur le dosage indirect du magnésium. Enfin on communique le mode d'exécution pratique pour la détermination de l'acide phosphorique et du magnésium dans une matière biologique, prenant pour base les conditions optimales, trouvées au cours du travail.

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Summary The principal methods for the determination of phosphoric acid in biological material are briefly enumerated, and the conclusion is reached that the colorimetric determination as molybdenum blue is the most reliable.The theoretical basis underlying the method is discussed, and the chemical and physico-chemical conditions enumerated which are necessary for the attainment of accurate results; the extension of the method to the indirect determination of magnesium is also considered. In conclusion, a practical procedure is proposed, based on the most favourable theoretical conditions, for the determination of both phosphoric acid and magnesium in biological material.

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Zusammenfassung Nach einer kurzen Aufzählung der hauptsächlichsten Methoden zur Bestimmung der Phosphorsäure in biologischem Material wird der Schluß gezogen, daß unter allen Methoden die kolorimetrische zur Bestimmung als Molybdänblau die vertrauenswürdigste ist.Es werden die theoretischen Grundlagen behandelt, auf denen diese Methode beruht, und die chemischen und physikochemischen Bedingungen diskutiert, deren Erfüllung zur Erreichung genauer Bestimmungen notwendig ist. Es wird auch die Ausdehnung der Methode auf die indirekte Bestimmung des Magnesiums in Betracht gezogen. Schließlich wird unter Zugrundelegung der als optimal festgestellten Bedingungen die praktische Ausführungsform sowohl für die Bestimmung der Phosphorsäure wie des Magnesiums in biologischem Material vorgeschlagen.

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Rissunto Fatta una rapida ressegna dei principali metodi di dosaggio dell'acido fosforico in materiale biologico, si conclude che fra tutti il metodo colorimetrico all'azzurro di molibdeno é quello che da maggior affidamento.Si trattano i fondamenti teorici su cui si basa tale metodo e si discutono le condizioni chemiiche e chimico-fisiche necessarie par arrivare a determinazioni esatte. Si contempla pure l'estensione del metodo al dosaggio indiretto del magnesio. Infine tenendo conto delle condizioni optimum stabilite, si propone il procedimento pratico di determinazione sia dell'acido fosforico sia del magnesio in materiale biologico.

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Diese Arbeit wurde noch von der früheren Schriftleitung der Mikrochemie redigiert.     

Determinazione di alcuni composti ossiantrachinonici a mezzo di titolazione in solventi non acquosi

Riassunto E stato applicato il metodo di titolazione potenziometrica con metilato sodico a composti fenolici aventi formula simile come l'1–8 diossiantrachinone, l'1–8 diossi-3-metilantrachinone e l'1–8 diossi-3-metil antrone, di notevole importanza farmaceutica.Come solvente si è usata la piridina e come rivelatori del punto di equivalenza una coppia di elettrodi vetro-antimonio non essendo possibile usare indicatori data la forte colorazione delle soluzioni.

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Summary Potentiometric titration with sodium methylate was used ton determine derivatives whose constitution is similar to that of 1,8-dihydroxyanthraquinone, 1,8-dihydroxy-3-methylanthraquinone and l,8-dihydroxy-3-methylanthrone.The solvent is pyridine. The change point was determined by means of an electrode pair: glass electrode-antimony electrode, since the intense self-color of the solutions excludes the use of indicators.

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Zusammenfassung Die potentiometrische Titration mit Natriummethylat wurde zur Bestimmung von Derivaten herangezogen, deren Zusammensetzung dem 1,8-Dihydroxyanthrachinon, dem 1,8-Dihidroxy-3-methylanthrachinon und dem 1,8-Dihidroxy-3-methylanthron ähnlich ist.Als Lösungsmittel wird Pyridin verwendet. Der Umschlagspunkt wird mit Hilfe eines Elektrodenpaares Glaselektrode-Antimonelektrode festgestellt, da die starke Eigenfärbung der Lösungen den Gebrauch von Indikatoren ausschließt.

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Résumé Le titrage potentiométrique par le méthylate de sodium a été appliqué au dosage de dérivés dont la composition est semblable à celles de la 1, 8-dihydroxyanthraquinone, de la 1,8-dihydroxy-3-méthylanthraquinone et de la l,8-dihydroxy-3-méthylanthrone. On utilise la pyridine comme solvant.Le point final de titrage est déterminé à l'aide d'un système électrode de verre: électrode d'antimoine car la forte coloration des solutions interdit l'emploi d'indicateurs.

     

Bestimmung per aktivierungsparameter per ringinversion sptro-substituierter cycloheptatriene

Ringinversion parameters of spiro-cycloheptatrienes $\text{1}$ - $\text{4}$ having been studied with the aid of line shape analysis show a small dependance on the spirobridge but a large one on sterical hindrance.     

Test strip enzyme immunoassays and the fast screening of nortestosterone and clenbuterol residues in urine samples at the parts per billion level

The preliminary results of an investigation into the development of "on-site" test strip enzyme immunoassays for the screening of urine samples for the presence of growth promoters, such as 17 beta, 19-nortestosterone and clenbuterol at the parts per billion level are described. Urine samples, enzyme-labelled analyte and a nitrocellulose test strip, containing immobilized antibodies, are incubated together, after which the strip is placed in a chromogen-containing substrate solution for colour reaction. Using prefabricated strips, the tests can be performed in 45-60 min. A similar assay was worked out using a dot-blotting device, allowing the test to be performed in 20-50 min. The tests are simple and easy to perform outside the laboratory. Urine samples identified positive by gas chromatography mass spectrometry were also found to be positive with these test strips and, so far, no false-positive results have been encountered. With standard additions to blank urine samples, positive samples could be distinguished above the 5 ng ml level. However, samples from treated calves contain one or more metabolites of the parent compound, which increase the sensitivity of the assays. Although the tests described can be improved and still have to be evaluated further by analysing more urine samples, the preliminary results are very promising and give a lead to further research into the applicability of such "on-site" tests in residue analysis.     

Development and validation of a capillary electrophoresis method for the determination of phenothiazines in human urine in the low nanogram per milliliter concentration range using field-amplified sample injection

A capillary zone electrophoresis (CZE) method with ultraviolet-visible detection has been established and validated for the determination of five phenothiazines: thiazinamium methylsulfate, promazine hydrochloride, chlorpromazine hydrochloride, thioridazine hydrochloride, and promethazine hydrochloride in human urine. Optimum separation was obtained on a 64.5 cm x 75 microm bubble cell capillary using a buffer containing 150 mM tris(hydroxymethyl)aminomethane and 25% acetonitrile at pH 8.2, with temperature and voltage of 25 degrees C and 20 kV, respectively. Naphazoline hydrochloride was used as an internal standard. Field-amplified sample injection (FASI) has been applied to improve the sensitivity of the detection. Considering the influence of parameters affecting the on-line preconcentration (nature of preinjection plug, sample solvent composition, injection times, and injection voltage) and due to the significant interactions among them, in this paper we propose for the first time the application of a multivariate approach to carry out the study. The optimized conditions were as follows: preinjection plug of water for 7 s at 50 mbar, electrokinetic injection for 40 s at 6.2 kV, and 32 microm of H3PO4 in the sample solvent. Also, a solid-phase extraction (SPE) procedure is developed to obtain low detection limits and an adequate selectivity for urine samples. The combination of SPE and FASI-CZE-UV allows adequate linearities and recoveries, low detection limits (from 2 to 5 ng/mL), and satisfactory precisions (3.0-7.2% for an intermediate RSD %).     

Self-assembled poly(imidazole-palladium): highly active, reusable catalyst at parts per million to parts per billion levels

Metalloenzymes are essential proteins with vital activity that promote high-efficiency enzymatic reactions. To ensure catalytic activity, stability, and reusability for safe, nontoxic, sustainable chemistry, and green organic synthesis, it is important to develop metalloenzyme-inspired polymer-supported metal catalysts. Here, we present a highly active, reusable, self-assembled catalyst of poly(imidazole-acrylamide) and palladium species inspired by metalloenzymes and apply our convolution methodology to the preparation of polymeric metal catalysts. Thus, a metalloenzyme-inspired polymeric imidazole Pd catalyst (MEPI-Pd) was readily prepared by the coordinative convolution of (NH(4))(2)PdCl(4) and poly[(N-vinylimidazole)-co-(N-isopropylacrylamide)(5)] in a methanol-water solution at 80 °C for 30 min. SEM observation revealed that MEPI-Pd has a globular-aggregated, self-assembled structure. TEM observation and XPS and EDX analyses indicated that PdCl(2) and Pd(0) nanoparticles were uniformly dispersed in MEPI-Pd. MEPI-Pd was utilized for the allylic arylation/alkenylation/vinylation of allylic esters and carbonates with aryl/alkenylboronic acids, vinylboronic acid esters, and tetraaryl borates. Even 0.8-40 mol ppm Pd of MEPI-Pd efficiently promoted allylic arylation/alkenylation/vinylation in alcohol and/or water with a catalytic turnover number (TON) of 20,000-1,250,000. Furthermore, MEPI-Pd efficiently promoted the Suzuki-Miyaura reaction of a variety of inactivated aryl chlorides as well as aryl bromides and iodides in water with a TON of up to 3,570,000. MEPI-Pd was reused for the allylic arylation and Suzuki-Miyaura reaction of an aryl chloride without loss of catalytic activity.     

One molecule per particle method for functionalising nanoparticles

A mean of one biotinylated dextran molecule per particle is conjugated to 15 nm gold nanoparticles, by a process of self-assembly, which depends on the relationship between dextran molecular weight and particle size.     

Building transition probabilities per collision from transition rates per unit time for finding the mean observable quantities in the gas phase

A new method of finding transition probabilities per collision from a set of transition rates per unit time is proposed. The problem is solved by introducing a normalization function that is easily derived from a recursion equation. The solution of recursion equation is obtained in the analytical form for the case of separable kernels. The Morse oscillator in a thermal bath is considered as an example.     

Indican determination in urine: Application for urine determination in adulterated cow milk

A spectrophotometric procedure for the determination of indican in urine based in Jolles' reaction, modified by Bermejo-Martínez and Barrera-Ramallo, is described; and it is applied for the determination of urine in adulterated cow milk, until addition of 2% human urine is estimated.     

Evolution of absorption energy per unit thickness of damaged sandstone

Journal of Thermal Analysis and Calorimetry - This paper experimentally studies the evolution of absorption energy characteristics per unit thickness of Jhiri sandstone at variable temperatures...     

Micro-Electrospray: Zeptomole/attomole per microliter sensitivity for peptides

The micro-electrospray ionization source has been optimized for the specific analysis of neuropeptides such as neurotensin and methionine enkephalin. The source has the option of integrating nanoliter flow-rate desalting and preconcentration techniques into the micro-electrospray spray needle, eliminating post-column dead volumes. For neurotensin, the most sensitive neuropeptide analyzed thus far in this work, the injection of 10 μL of a solution containing 320 zeptomolesy/gmL gave an [M + 3H]⁺³ ion at m/z 558.4 with S/N of > 8∶1. The MS/MS analysis of this peptide for the fragment ion at m/z 578.9 gave a S/N > 20∶1 for a solution containing 32 attomoles/μL.