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PubMed1995

Determination of butyltin metabolites in the mouse liver by flameless atomic absorption spectrophotometry.

A new analytical method for observation of the metabolic status of butyltin compounds in the mouse liver was devised by a combination of extraction, purification and separation followed by quantitative analysis of each butyltin compound. After the extraction of all tin compounds from liver homogenate with ethyl acetate, these compounds were purified by combination of the fractional extract with organic solvents and column chromatography. The purified fraction was also analyzed by thin-layer chromatography, identifying each tin compound from differences in mobility on a silica gel plate. The tin content in the each separated spot on the plates was measured by flameless atomic absorption spectrophotometry after extraction by acid treatment. About 90% of tin was recovered by this method from the liver of mice which had been administered tri- or dibutyltin compound orally. This method will be useful for quantification of each metabolic product formed from butyltin compounds in vivo.

Animals↗
PubMed1991

Quantitative determination of non-haem iron and ferritin iron in bone marrow using flameless atomic absorption spectrophotometry. A comparative study on the cytological and chemical determination of the bone marrow iron content.

A method for non-haem iron analysis in bone marrow aspirates using graphite furnace atomic absorption spectrophotometry has been developed. Bone marrow aspirates were obtained from patients with various disorders. A good correlation is observed between chemical and cytological assessment of total non-haem iron in bone marrow. An intra-assay coefficient of variation of 9.0% was observed. The ferritin-iron concentration was also determined and a CVduplo of 11% was found. The ferritin iron concentration increased with an increasing total iron content until saturation of ferritin appeared to be reached at about 3 g ferritin per kg protein. It was concluded that the quantitative determination of bone marrow iron can be of value in the diagnosis and investigation of both hypo- and hyper-ferraemic disorders.

Bone Marrow↗
PubMed1996

Determination of plasma protein-bound malondialdehyde by derivative spectrophotometry.

We describe a method for the measurement of protein-bound malondialdehyde with the thiobarbituric acid reaction in human plasma using second-derivative spectrophotometry. Calibration was done by spectrum height measurement from the baseline at 532 nm. The data were compared with those obtained by using conventional absorbance and fluorimetric measurements. The results were linear from 0.2 to 80 mumol/l and the detection limit was 0.19 mumol/l. Within-run and between-run precision, evaluated by analysing pooled normal plasma, were 8 and 14% respectively. The method was tested for the influence of bilirubin, haemoglobin, glucose, urea, uric acid, sucrose and N-acetyl-neuraminic acid which interfered in the colorimetric method but not in the technique proposed here. The mean (+/-SD) malondialdehyde concentration determined in 59 healthy blood donors with the new assay was 0.34 (+/-0.14) mumol/l. This assay procedure could represent an alternative to high-performance liquid chromatography for the measurement of malondialdehyde in biological media.

Blood Proteins↗
PubMed1989

Laser spectrophotometry in the fetus.

Laser spectrophotometry with near-infrared light is newly available for clinical application. The equipment consists of a near-infrared datacollection unit (NIRDCU) and apersonal computer. Emission of laser light at wavelengths of 775, 805, 845 and 904 nm is provided by the four laserdiodes of the NIRDCU. By analyzing changes of optical density during laser radiation, information is achieved about the intracellular redoxstate and relative changes of blood volume. During measurement with the system on fetal head we were able to get a first impression of the methods potential. While the application of the laser sensors is still cumbersome, signals providing information of the relative changes of hemoglobine concentrations, relative changes of blood volume and cytochrome aa3 seem achievable. Laser spectrophotometric monitors may become save, low cost and portable instruments for the noninvasive assessment of the biochemical and biophysical status in the fetus.

Fetal Monitoring↗
PubMed2003

Determining of crystalline silica in respirable dust samples by infrared spectrophotometry in the presence of interferences.

Infrared Spectrophotometry (IR) is now widely used to determine crystalline silica in industrial dust samples. Though the IR method has many advantages when dealing with respirable dust samples, some serious analytical errors are often caused by interference minerals contamination. These minerals have a characteristic absorption band corresponding in position to the analytical peak for crystalline silica. In this paper, six typical interference minerals (Kaolinite, Mullite, Muscovite, Pyrophyllite, Montmorillonite and Amorphous silica) were pre-size controlled to respirable range and their infrared spectra were measured by means of an FT-IR with the well-known potassium bromide tablet technique. The effects of these interference minerals on the Japanese OEL or the administrative control level for respirable dust which depend on the silica content were calculated and expressed in figures. The measured absorption coefficients of the interference minerals and quartz were 1.36-6.98 Abs/mg and 24.46 Abs/mg, respectively. The absorption band height ratios of each interference minerals were also measured. Then the efficiency and applicability of two spectrum correction methods for the interference minerals, absorbance ratio method and difference spectrum method were examined by using artificially mixed samples (standard interference mineral + standard quartz). By comparing the quantifying results for the mixture samples, it was revealed that the interfered spectra were almost corrected successfully when using the difference spectrum method, whereas correction by the absorbance ratio method resulted in apparent negative errors. Furthermore, the difference spectrum method was proven to be superior to the absorbance ratio method in applicability.

Dust↗
PubMedDate not supplied

Comparison of nonmetal and metal hydrophilic photosensitizer, ATX-S10 (Na) and ATN-2, binding with human serum proteins using spectrophotometry.

Intermolecular interactions of human serum proteins with a hydrophilic nonmetalloporphyrin, 13,17-bis(1-carboxypropionyl)carbomoylethyl-8-ethenyl-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetramethylporphyrin sodium salt (ATX-S10 (Na)), or a hydrophilic gallium-metalloporphyrin, diethylenetriamine pentaacetic acid ester of 2-[1-(2-hydroxy-ethoxy)ethyl]-4-vinyl-deuteroporphyrin (IX) Ga complex (ATN-2), were investigated using spectrophotometry. ATX-S10 (Na) caused a bathochromic shift with albumin, high-density lipoprotein and low-density lipoprotein, but little or no shift was observed with hemopexin, transferrin and immunoglobulin G. In contrast, ATN-2 displayed a bathochromic shift only with hemopexin. These results suggest that the association energy of ATX-S10 (Na) with albumin might be slightly greater than that with lipoproteins and that of ATN-2 with hemopexin might be greater than that with other serum proteins.

Blood Proteins↗
PubMed2003

Diagnosis of Smith-Lemli-Opitz syndrome by ultraviolet spectrophotometry.

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder due to an inborn error of cholesterol metabolism, characterized by congenital malformations, dysmorphism of multiple organs, mental retardation and delayed neuropsychomotor development resulting from cholesterol biosynthesis deficiency. A defect in 3 -hydroxysteroid-delta7-reductase (delta7-sterol-reductase), responsible for the conversion of 7-dehydrocholesterol (7-DHC) to cholesterol, causes an increase in 7-DHC and frequently reduces plasma cholesterol levels. The clinical diagnosis of SLOS cannot always be conclusive because of the remarkable variability of clinical expression of the disorder. Thus, confirmation by the measurement of plasma 7-DHC levels is needed. In the present study, we used a simple, fast, and selective method based on ultraviolet spectrophotometry to measure 7-DHC in order to diagnose SLOS. 7-DHC was extracted serially from 200 l plasma with ethanol and n-hexane and the absorbance at 234 and 282 nm was determined. The method was applied to negative control plasma samples from 23 normal individuals and from 6 cases of suspected SLOS. The method was adequate and reliable and 2 SLOS cases were diagnosed.

Biomarkers↗
PubMed2006

The detection of salivary minerals in smokers and non-smokers with chronic periodontitis by the inductively coupled plasma-atomic emission spectrophotometry technique.

BACKGROUND: The purpose of this study was to evaluate the effect of smoking on the salivary minerals in subjects with chronic periodontitis by the inductively coupled plasma-atomic emission spectrophotometry (ICP-AES) technique. METHODS: The study group included 24 subjects-12 smokers and 12 non-smokers-with chronic periodontitis. Clinical measurements and non-stimulated whole saliva were obtained, and the levels of five elements-sodium, potassium, calcium, magnesium, and phosphate-in each specimen were analyzed. RESULTS: When the clinical parameters were compared between groups, only plaque index was significantly higher in smokers than non-smokers (P <0.05). The mean plaque index of smokers and non-smokers was 1.93 +/- 0.51 and 1.51 +/- 0.39, respectively. The results of this study showed that there were no significant differences between groups in the mineral content of saliva. In smokers, there were positive correlations between the levels of calcium, sodium, and magnesium and clinical attachment level. There was also a positive correlation between the level of phosphate and the percentage of bleeding on probing. In non-smokers, there was a negative correlation only between the mean level of sodium and plaque index (P <0.05). CONCLUSIONS: The present study showed that no significant differences were found between the mineral content of saliva of smokers and non-smokers by the ICP-AES technique. It is a useful, fast, and sensitive technique compared to other techniques, and it can be advised for researchers while analyzing the mineral content of saliva.

Adult↗
PubMed2005

Numerical taxonomy characterization of Baccharis genus species by ultraviolet-visible spectrophotometry.

Numerical taxonomy characterization of Baccharis genus species was performed using ultraviolet-visible spectrophotometry. The aim was to present a more convenient, more practical, more economic and faster method based on chemometric methods and UV-vis absorbance to give the most information about species identity and discrimination, especially when their classification has been doubtful. Three Baccharis species: B. genistelloides Persoon var. trimera (Less.) DC, B. milleflora (Less.) DC, and B. articulata (Lam.) Persoon were included in the study. With the help of principal component analysis (PCA) and cluster analysis (CA), we could characterize the three species. Application of soft independent modeling of class analogy (SIMCA) and K-nearest neighbor (KNN) methods on a training set of 65 extracts resulted in models that correctly classified all samples of an independent validation set, eight samples of B. genistelloides Persoon var. trimera (Less.) DC and one sample donated by Prof. Alarich Schultz Herbarium, Porto Alegre-RS, Brazil.

Baccharis↗
PubMed2006

On-line electrochemical oxidation of Cr(III) for the determination of total Cr by flow injection-solid phase spectrophotometry.

A novel on-line oxidation method of ultra-trace Cr(III) dissolved in natural water has been developed using a flow electrolysis cell. This method was successfully applied to the determination of the total Cr concentration by flow injection-solid phase spectrophotometry using diphenylcarbazide as a coloring agent. With the applied potential of 1.35 V (vs. Ag/AgCl) and the flow rate of 0.80 cm(3) min(-1), Cr(III) was quantitatively oxidized to Cr(VI) at room temperature. The total Cr concentration of sub-microg dm(-3) in 3 - 4 samples could be determined within 1 h using an aqueous sample volume of 7.1 cm(3). The analytical values of the total Cr concentration in natural water were in good agreement with those obtained by ICP-MS. The detection limit of the proposed method was 0.014 microg dm(-3) (3sigma, n = 7). This method could be applied to the specific determination of Cr(III) and Cr(VI) in river water samples.

Chromium↗
PubMed2006

Determination of mercury in fish by cold vapor atomic absorption spectrophotometry using a multicommuted flow injection analysis system.

A flow system was developed for the determination of total mercury concentration in fish samples by cold vapor atomic absorption spectrophotometry (CVAAS), based on the multicommuted flow injection analysis (MCFIA) approach. The system uses independently controlled solenoid valves for the introduction of reagents and samples. When not injected, solutions were recirculating to the reservoir bottles, in this way reducing the waste produced by the analytical system and also the sample consumption. Results were compared to those obtained by the reference flow injection procedure. Accuracy was also assessed by recovery studies using a certified reference material as well as spiked samples; recovery percentages in the range of 90.7% to 99.8% were found. The repeatability of the method was better than 6.0% (RSD, n = 10). A limit of detection of 4.8 microg of mercury per kg of fresh fish sample was achieved. The total waste produced was reduced to 30% of that from the reference flow injection CVAAS procedure.

Animals↗
PubMed1996

Direct quantitative analysis of respirable cristobalite on filter by infrared spectrophotometry.

A direct on-filter method in infrared spectrophotometry was investigated for the quantitative analysis of respirable cristobalite. A polypropylene membrane filter was employed for this analysis, because the membrane filter has high transparency and no interference peak in the spectral range to be used (750-250 cm-1). Linear relation between the sample weight and peak height (absorbance) for three specific peaks at 620, 385 and 300 cm-1 of cristobalite were confirmed over the range from 45 to 1,000 micrograms/cm2 for 620 cm-1 peak and 45-2,380 micrograms/cm2 for 385 and 300 cm-1 peaks. The variation of absorbance with the difference of particle size was smaller in filter sample than in potassium bromide pellet sample. As a conclusion, this direct on-filter method can be used for quantitative analysis of cristobalite in airborne dust in working environment.

Air Pollution, Indoor↗
PubMed1980

Determination of serum-phosphate without deproteinization by ultraviolet spectrophotometry of the phosphomolybdic acid complex.

Phosphate may be determined in serum without deproteinization as the phosphomolybdic acid complex by UV-spectrophotometry. The rate of complex formation is dependent on the acidity and the concentration of molybdate. The photometric measurements should be performed at a longer wavelength than in maximum absorptivity of the phosphomolybdic acid complex to permit practical high concentrations of molybdate in the reagents. Citric acid will hinder the complex formation, but will not interfere with the stability of the phosphomolydbic acid. The phosphomolybdic complex is determined by adding citric acid to the samples before (blank) and after (test) the molybdate. The analytical procedure has been automated on a Greiner GSA II, Greiner Electronics, Switzerland.

Humans↗
PubMed1984

Determination of zinc in erythrocytes, granulocytes and serum by flame atomic absorption spectrophotometry.

Zinc was determined in granulocytes, erythrocytes and serum by flame atomic absorption spectrophotometry. Using a Teflon sampling cup, the sample volume for a single granulocyte zinc determination was reduced to 100 microliter. Zinc in serum and erythrocytes was measured by aspirating the sample at a rate of 5 ml/min. The total volume of blood used was 23-28 ml. The intra-assay coefficient of variation of the method for granulocytes was 0.01 and of the method for serum and erythrocytes 0.018. The corresponding inter-assay coefficient of variation was 0.037 and 0.03, respectively. Recovery of zinc determined by the method of aspirating the small volume (100 microliter) was 103% and by the method of aspirating 5 ml/min 97%. The coefficient of correlation between the two methods was r = 0.9968.

Adult↗
PubMed1981

The composition of urinary stones analysed by infrared spectrophotometry and the precipitation of calcium phosphates from saturated solutions.

Of 205 consecutively analysed urinary stones, two-thirds were from men, which reflected the male: female ratio of urolithiasis cases at this hospital in the period of the study. Phosphate was found in 69.9% of the stones from male patients and in 94.2% of those from female patients. The phosphate in the urinary stones consisted of hydroxylapatite, carboxylapatite and/or MgHN4PO4. CaHPO4 could be demonstrated in only six of the 205 stones. Oxalate was present in 59.6 and 39.1% of the stones from males and females, respectively. Calcium phosphates from saturated solutions precipitated mainly as hydroxylapatite at pH levels above 5.47. Only below this level did CaHPO4 become visible in infrared spectrophotometry analysis. The solubility of calcium phosphates greatly increased with lowering of the pH. Increasing the ionic activity of the saturated solution with sodium chloride increased the solubility of calcium phosphates only to a limited extent.

Adult↗
PubMed1991

Collagenolytic enzymes assayed by spectrophotometry with suspensions of reconstituted collagen fibrils.

Collagenolytic enzymes were quantitated by a method based on spectrophotometry of suspended reconstituted collagen fibrils. To obtain optically stable suspensions it was necessary to perform a short sonication of the aggregated fibrils at 10 degrees C. When fibrils were cleaved with mammalian fibroblast collagenase at 35 degrees C the triple helical collagen fragments (TCA and TCB) would uncoil spontaneously and the decreasing turbidity was used as an estimate of enzyme activity. The method is a specific collagenase assay since a possible cleavage in the non-helical parts of the collagen molecule with contaminating proteinases is without effect on the turbidity of the suspension and the collagen substrate is not converted to gelatin at 35 degrees C. After 1 h of incubation 0.2 U (equivalent to 0.2 micrograms) of fibroblast collagenase could be detected. In purification procedures with microbial collagenases many fractions were tested by overnight incubations in disposable cuvettes. Sealing of cuvettes with square silicone stoppers allowed rotation of enzyme-substrate mixtures directly in the cuvettes. Only standard laboratory equipment is required for this assay, which is not dependent on radiolabeling or preparation of specific immunologic reagents.

Animals↗
PubMed1995

Amputation level assessment using lightguide spectrophotometry.

The aim of this experimental study was to investigate whether lightguide spectrophotometry in the visible wavelength range in skin could be used to predict stump healing viability in patients with critical lower limb ischaemia. Remission spectra recorded at two sites (medial and lateral) on the line of a proposed trans-tibial amputation (TTA) and at 10mm intervals along the leg were analysed to give haemoglobin oxygenation (SO2). Degree of tissue hypoxia (DTH) along the leg was defined as the percentage of values along the leg less than 10% SO2. DTH and mean SO2 values were compared with skin blood flow values ((I125) 4-Iodoantipyrine clearance technique) and clinical outcome of trans-tibial amputation, (TTA) or trans-femoral amputation (TFA), in 41 patients. SO2 histograms were also measured in 12 normal subjects for comparison. The results of the study allowed the establishment of criteria for the accurate prediction of flap healing potential. Successful TTAs all displayed a minimum mean SO2 at the medial and lateral measurement sites of 30%, together with a maximum degree of tissue hypoxia of 15% along the limb. The combination of these criteria gave a sensitivity and selectivity of 1.0 for prediction of a successful outcome of TTA.

Amputation, Surgical↗
PubMed1975

Potential sources of copper contamination of farm milk supplies measured by atomic absorption spectrophotometry.

A method was developed to use atomic absorption spectrophotometry for copper measurements in milk filtrates prepared from equal volumes of milk and 20% trichloracetic acid. Results are reported for 11 farms for water supplies, wash and rinse solutions, and milk. Copper below 10 mug/liter was found at the well for the 5 farms with their own spring supply. Averages and ranges for all 11 farms in mug/liter were 33 (0 to 156) at the cold water tap in the milk house, 220 (8 to 1,360) at the hot water tap, 246 (8 to 1,722) in the wash sink with added detergent and hot water, and 275 (9 to 1,823) after using the wash solution. Rinse solution with hypochlorite in cold water showed a rise from 31 (1 to 157) before use to 51 (5 to 206) after use. Copper in milk averaged 99 mug/liter (72 to 163). In spite of relatively high copper in wash solutions, copper in milk was not correlated postively, giving rise to question whether adsorbed copper from such solutions can contribute much copper to milk. Thorough rinsing with low copper cold water and a high dilution ratio in milk were seen as mitigating factors. Direct contact of milk with copper bearing metals presented a greater opportunity for contamination. Removal of substantial amounts of copper from pipe lines and bulk tanks with sulfamic acid was demonstrated.

Agriculture↗