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A new synthetic medium having negligible ultraviolet absorbance is described for growing staphylococci in experiments requiring ultraviolet spectrophotometry of cell-free portions of the culture.
The metabolic pathway used by Rhodococcus sp. BPG-8 isolated from oil-rich soil in Newfoundland for the degradation of 1,3,5-trihydroxybenzene (phloroglucinol) as a sole source of carbon and energy was determined. Culture filtrates of cells grown on phloroglucinol detected 1,2,3,5-tetrahydroxybenzene when extracted and analyzed using gas chromatography--mass spectrometry, thin-layer chromatography, and ultraviolet spectrophotometry. Nonaromatics were either derivatized with 2,4-dinitrophenylhydrazine and compared against authentic standards by the above methods, or detected by chemical and enzymatic methods. Extracts of cells grown on phloroglucinol contained phloroglucinol hydroxylase activity, and a dioxygenase that carried out ortho-cleavage of 1,2,3,5-tetrahydroxybenzene. The extract also showed inducible activity for further metabolism of acetopyruvate leading to accumulation of formate in the supernatant. A tentative degradative pathway for phloroglucinol by Rhodococcus sp. BPG--8 is proposed.
An evaluation of an enzyme immunoassay for the determination of theophylline in serum (EMIT, Syva Corp.) is presented. The EMIT assay was fully mechanized by the use of an Eppendorf analyzer 5010. The precision of this enzyme immunoassay was satisfactory (coefficients of variation from day to day ranged from 5--6%). The EMIT assay proved to be specific, rapid and easy to perform. A comparison of the results obtained by EMIT and ultraviolet spectrophotometry in a series of 100 patients showed a good correlation between both methods.
The authors studied the availability of parenteral solutions of diazepam in glass bottles or polyethylene (PE) containers during infusion through polyvinyl chloride (PVC) administration sets. Diazepam solutions in concentration of 1000 mg/500 ml in 0.9% sodium chloride (NS) and 5% glucose (G5W) injection were infused at a flow rate of 30 ml/h, and samples were taken from the bottle and at the end of the administration set, till 12 hours of infusion. The samples were tested in triplicate using ultraviolet spectrophotometry. The greatest loss of diazepam was observed in all solutions at 30 minutes of infusion (63.5% G5W glass, 60.5% NS glass, 55% G5W PE and 58% NS PE from the original concentration of 200 micrograms/ml). The diazepam concentrations in the containers did not significantly changed. The loss of diazepam from solutions infused through PVC administration sets should be kept in mind in severe clinical situations as status epilepticus, tetanus and eclampsia.
OBJECTIVE: To characterize the activity of catalase in equine semen. ANIMALS: 15 stallions of known and unknown reproductive history. PROCEDURE: Seminal plasma was collected from raw equine semen by centrifugation, and samples of seminal plasma were frozen prior to assay for catalase activity. Tissue samples (n = 3 stallions) from the bulbourethral gland, prostate gland, vesicular gland, and testis were homogenized, and cauda epididymal fluid was collected for determination of catalase activity. Catalase activity was determined as an enzyme kinetic assay by the disappearance of H2O2 as measured by ultraviolet spectrophotometry. RESULTS: Catalase activity in equine seminal plasma was 989.3 +/- 1678 U/ml (mean +/- SEM), and the specific activity of catalase in equine seminal plasma was 98.7 +/- 29.2 U/mg of protein. Specific activity of catalase in tissue homogenates was significantly higher in the prostate gland (954 +/- 270 U/mg of protein) than in the ampulla (59 +/- 5 U/mg of protein), bulbourethral gland (54 +/- 11 U/mg of protein), vesicular gland (39 +/- 3 U/mg of protein), cauda epididymal fluid (11 +/- 3 U/mg protein), or testis (54 +/- 6 U/mg of protein). CONCLUSIONS AND CLINICAL RELEVANCE: Equine seminal plasma contains a high activity of catalase that is derived primarily from prostatic secretions. Procedures such as semen cryopreservation that remove most seminal plasma from semen may reduce the ability to scavenge H2O2 and thereby increase the susceptibility of spermatozoa to oxidative stress.
The purpose of the study was to determine the solubility and the intrinsic rates of dissolution of three crystal modifications, two anhydrate, and one dihydrate of alprazolam, a 1,4-benzodiazepine derivative. Solubility was determined by ultraviolet spectrophotometry at different levels of pH, and intrinsic dissolution rates were determined by a rotating disk method. The apparent solubility of alprazolam crystal modifications was dependent on pH, being 8-10 mg/ml at pH 1.6 and 0.1 mg/ml at pH 5.0. The apparent solubility values for the anhydrate forms were similar, whereas the hydrate form showed lower apparent solubility at each pH. The mean intrinsic rates of dissolution for the anhydrate forms were 16 and 18 micrograms cm-2 min-1, and for the dihydrate modification 21 micrograms cm-2 min-1 at 50 rpm, respectively. At 75 rpm, the corresponding values were 22, 22, and 27 micrograms cm-2 min-1. The rate of intrinsic dissolution was also dependent on the pH. It can be concluded that the apparent solubility and the intrinsic dissolution rate of the anhydrate and hydrate forms were different. The obtained apparent solubility values at different levels of pH for the water-solvated crystal modification were evidently lower than those of the two anhydrate forms studied. Furthermore, the intrinsic rate of dissolution was significantly (p < 0.05) higher for the hydrate form of alprazolam.
Alfa- and delta forms of cephalosporin were compared. Biological activity, lantimicrobial spectrum and innocuousness of the forms and their physico-chemical properties were investigated with the methods of infrared and ultraviolet spectrophotometry and derivatography. No significant differences in the biological properties of alfa- and delta forms of cephalosporin were found. However, the ingrared spectrum of the delta-form was indicative of higher stability of its molecule, which was confirmed by higher thermostability of delta-cephalosporin.
Bendroflumethiazide and cyclothiazide are eluted from a sodium carbonate column with chloroform-acetic acid (98+2) and are measured directly by ultraviolet spectrophotometry. The method was collaboratively studied by 8 analysts. The average per cent recovery and standard deviations for simulated mixes of bendroflumethiazide and cyclothiazide were 99.61+/-0.78 and 99.3+/-1.97. The method has been adopted as official first action for the determination of bendroflumethiazide.
A method for the separation of derivatized saccharides in tobacco with high performance capillary electrophoresis and ultraviolet spectrophotometry (HPCE-UV) is presented. Five saccharides in tobacco were derivatized with p-aminobenzonitrile, separated at pH 10.5 with 50 mmol/L borate buffer containing 5% (volume fraction, the same in the following percentage concentration) methanol, 5% acetonitrile, 2.5% ethyleneglycol, 2.5% 2-propanol and 1 mmol/L sodium dodecyl sulfate, and detected at 285 nm.
With the preparation of borneol-beta-cyclodextrin inclusion compound, the stability of the product was improved. In the studies on quality standards, TLC method was used in the identification of three medicinal ingredients and TLC-ultraviolet spectrophotometry was used in the content determination of the chemical constituent tanshinone II A in Salvia miltiorrhiza.
By use of chemical and physicochemical methods the qualitative and quantitative analysis of bacteriostatic agents N-carbamoylmethylhexamethylenetetraamonium chloride (U-77) and 1-propyl-1,10-phenanthrolinium iodide (X-50) was carried out. The color reactions of these salts with various agents, e. g., concentrated acids, precipitants, oxidizers, indicators, ninhydrin, salts of heavy metals were assesssed. Some characteristic color reactions were found for analysis of quaternary ammonium salts. Experimental results indicate that interaction of N-carbamoylmethyhexamethylenetetraammonium chloride with silver nitrate leads to precipitate of the free silver in the form of a mirror under the proper conditions. It is a result of degradation of hexamethylenetetramine to formaldehyde and its oxidation, which is accompanied by reduction of silver ion to free silver. By use of thin-layer chromatography and ultraviolet spectrophotometry the physicochemical properties of compounds were tested. The suitability of qualitative methods, such as argentometry, mercurimetry, iodometry, extraction photometric analysis was detected. The results suggest, that the most suitable and precise method is argentometry.
Charge-transfer (CT) reaction of chloranil (TCBQ) as a pi-electron acceptor with fleroxacin (FLX) as an electron donor has been studied by ultraviolet spectrophotometry method. Experiment showed that FLX reacted with TCBQ in sodium dodecyl sulfate (SDS) micellar systems, and a stable complex was formed and the absorbency was remarkably enhanced. Therefore, a simple, rapid, accurate and sensitive method for the determination of FLX has been developed. Beer's law is obeyed in the range of 0.6-24 mg x L(-1) of FLX and r = 0.9993. The apparent molar absorptivity of CT complexes at 326 nm is 3.3 x 10(4) L x mol(-1) x cm(-1). The composition of CT complex was found to be 1:1 by Bent-French and curved intersection methods. The proposed method has been applied to the determination of ESL in tablets. The recoveries are 99.2%-99.7%. The relative standard deviation is 0.7%-2.1%. The proposed methods are suitable for the routine quality control of drug alone and in tablets or capsules without fear of interference caused by the excipients expected to be present in tablets or capsules.
The interaction structures and optical properties of host-guest of cucurbit[n=6-8]urils with synthesized three imidazo-[4,5, f]1,10-phenathroline derivates were investigated by using 1HNMR technique, fluorescence spectrophotometry, and ultraviolet spectrophotometry. The experimental results reveal that cucurbit [6] uril (Q[6]) can only interact with guest salt of 2-(4-methyl)-phenyl-imidazo-[4,5,f]1,10-phenathroline (W1) with a ratio of 1:1; however, cucurbit [7] uril (Q[7]) can interact with all three guest salts of 2-(4-methylphenyl)-imidazo-[4,5,f]1,10-phenathroline(W1), 2-(2-methylphenyl)-imidazo-[4,5,f] 1,10-phenathroline(W2), and 2-(3-methyloxyl phenyl)-imidazo-[4,5,f]1,10-phenathroline(W3) with the same ratio of 1:1; cucurbit [8] uril (Q[8]), except interaction with W1 with a ratio of 1:2, can also interact with W2 and W3 with a ratio of 1:1.
The procedure for anticonvulsant analysis represent use of a relatively new technology. The procedures compare favorably in accuracy and precision with accepted methodology using gas chromatography [14]. It is possible to determine a greater number of anticonvulsants simultaneously with liquid chromatography than with reported gas-chromatographic procedures. This is because gas chromatography necessitates manipulation of the sample to be analyzed, the various components of which may have completely different manipulation requirements. Liquid chromatography is able to effect the analysis without extensive manipulation of the sample. The columns recommended in Sect. III are currently available standard columns. Column technology is developing at an accelerating rate. It is now anticipated that new developments in microparticulate packings and improvements in packing techniques will give the analyst greater column efficiency. This may be used either to shorten overall analysis time or to include more drugs in a simultaneous analysis. There is not yet available to the analyst a variety of different detectors suitable for routine use. This situation will change. In the case of the successful use of ultraviolet spectrophotometric detectors, the technique is not being fully exploited. Ultraviolet spectrophotometry is firmly established in practice, but as yet it is not routine to apply dual-wavelength spectroscopy to the column effluent. Application of this technique may be expected to improve selectivity and quantitation besides permitting optical resolution of some components that are not separated by the column. In the procedures given in this chapter there was no detailed discussion on gradient elution. This technique is potentially of great utility for simultaneous analyses of many compounds. It should be used only where isocratic elution is out of the question because it calls for somewhat stricter requirements of equipment in control of chromatography conditions. An additional time for equilibration between analyses may be considered too high a price to pay for any advantage gradient elution may give the analyst. The problem of fully automatic operation of liquid chromatographs for the type of analysis discussed here remains to be solved. Automatic operation would advance the use of liquid chromatography in the clinical laboratory probably more than any other single improvement. However, regardless of refinements of this type, liquid chromatography in its modern manifestation has versatility and sensitivity in abundance for analyzing compounds of toxicological and clinical interest. It will therefore assume greater importance in these areas.
This paper reviews analytical techniques for the detection and identification of amphetamines and amphetamine-like substances in non-biological samples. It shows the wide range of methods available, from simple testing procedures to the use of the most powerful instruments available in analytical chemistry. The following techniques are discussed: colour tests, microcrystal tests, ultraviolet spectrophotometry, fluorescence spectrometry, infra-red and Raman spectrophotometry, thin-layer chromatography, gas chromatography and high performance liquid chromatography.
Proteins and other interfering substances are precipitated from soy sauce, using sodium tungstate under acidic conditions. After centrifugation, the supernate is successively extracted with ethyl ether to isolate the benzoic acid in the organic solvent. The ethyl ether extract is washed with dilute HCl. Benzoic acid is then quantitatively determined by ultraviolet spectrophotometry. Recovery of sodium benzoate added to soy sauce ranged from 94 to 104%.
Succinyladenosine and succinylaminoimidazole carboxamide riboside were found in body fluids from 3 children, including a brother and sister, with severe psychomotor delay and autism. Both succinylpurines were identified by acid hydrolysis, anion-exchange chromatography, and ultraviolet spectrophotometry. Concentrations of both compounds were around 100 mumol/l in cerebrospinal fluid, between 5 and 10 mumol/l in plasma, and in the mmol/l range in urine. Succinylpurines were undetectable in cerebrospinal fluid and plasma from controls but there might be trace amounts in normal urine. The compounds are dephosphorylated derivatives of the intracellular metabolites adenylosuccinate and succinylaminoimidazole carboxamide ribotide, the two substrates of adenylosuccinase (adenylosuccinate lyase, EC 4.3.2.2). Their presence indicates a deficiency of this enzyme, which is involved in both de novo synthesis of purines and the formation of adenosine monophosphate from inosine monophosphate. Assays in one patient revealed markedly decreased adenylosuccinase activity in the liver and absence of activity in the kidney. The accumulation of both succinylpurines in the cerebrospinal fluid suggests that there is also a deficiency of this enzyme in the brain and that it may be the basic defect in a subgroup of children with genetically determined autism.
Toxicological and pathological findings are described in fatalities involving pentazocine (Talwin) and tripelennamine (Pyribenzamine). Procedures using thin-layer chromatography, gas chromatography, ultraviolet spectrophotometry, and spectrophotofluorometry are described, as well as the quantitative analysis of biological specimens of drug abuse and homicide victims. Microscopic findings in lung specimens from drug abuse deaths are also described.