scholarly journals Detection of saccharides using diazo-compound as a color reagent.

1995 ◽  
Vol 44 (5) ◽  
pp. 377-382 ◽  
Author(s):  
Yuji SUZUKI ◽  
Yoshikatsu SAKAGISHI
Keyword(s):  
Diazo Compound ◽  
Color Reagent

scholarly journals Unlocking a Diazirine Long-Lived Nuclear Singlet State via Photochemistry: NMR Detection and Lifetime of an Unstabilized Diazo-Compound

2018 ◽  
Vol 140 (48) ◽  
pp. 16855-16864 ◽  
Author(s):  
Barbara Procacci ◽  
Soumya S. Roy ◽  
Philip Norcott ◽  
Norman Turner ◽  
Simon B. Duckett
Keyword(s):  
Singlet State ◽  
Diazo Compound

scholarly journals Molecular iodine-catalyzed one-pot multicomponent synthesis of 5-amino-4-(arylselanyl)-1H-pyrazoles

2018 ◽  
Vol 14 ◽  
pp. 2789-2798 ◽  
Author(s):  
Camila S Pires ◽  
Daniela H de Oliveira ◽  
Maria R B Pontel ◽  
Jean C Kazmierczak ◽  
Roberta Cargnelutti ◽  
...  
Keyword(s):  
Multicomponent Reaction ◽  
Functional Group ◽  
Diazo Compound ◽  
Molecular Iodine ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
X Ray ◽  
Dehydrogenative Coupling ◽  
Reflux Temperature

A one-pot iodine-catalyzed multicomponent reaction has been developed for the selective preparation of 5-amino-4-(arylselanyl)-1H-pyrazoles from a diverse array of benzoylacetonitriles, arylhydrazines and diaryl diselenides. The reactions were conducted in MeCN as solvent at reflux temperature under air. The methodology presents a large functional group tolerance to electron-deficient, electron-rich, and bulky substituents and gave the expected products in good to excellent yields. The synthesized 1,3-diphenyl-4-(phenylselanyl)-1H-pyrazol-5-amine was submitted to an oxidative dehydrogenative coupling to produce a diazo compound confirmed by X-ray analysis.

scholarly journals NEW, GREEN AND MINIATURIZED ANALYTICAL METHOD FOR DETERMINATION OF CEFADROXIL MONOHYDRATE IN CAPSULES

2019 ◽  
Vol 3 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Bianca Marco ◽  
Ana Kogawa ◽  
Hérida Salgado
Keyword(s):  
Analytical Chemistry ◽  
Standard Sample ◽  
Low Cost ◽  
Visible Region ◽  
Hplc Method ◽  
Minimal Amount ◽  
Green Analytical Chemistry ◽  
Color Reagent ◽  
Routine Quality Control

Cefadroxil, an oral antimicrobial, presents few techniques optimized for the reduction of solvents and toxic residues and/or non-use of them. So, a quantitative, new and miniaturized method for determination of cefadroxil monohydrate in capsules has been developed and validated by spectrophotometric method in the visible region according to the international guidelines. The analyzes were performed using microplates containing 96 wells, 1 % of phenolphthalein and sodium hydroxide 0.1 M as reagent at 552 nm. The method was (i) linear in the range of 15-115 µg mL-1, (ii) selective when comparing standard, sample, adjuvants and color reagent, (iii) precise with deviations below 4 %, (iv) accurate when comparing the proposed method with the HPLC method, (v) robusts by making small and deliberate modifications to the method, (vi) besides being fast, low cost, eco-friendly and generates minimal amount of waste. The method can be applied to the routine quality control of cefadroxil monohydrate in capsules and an effective and accessible alternative that contemplates the concepts of current and sustainable green analytical chemistry.

Examination of Calculations and Colorimetric Procedures in the Chemical Evaluation of Vitamin D

1965 ◽  
Vol 48 (4) ◽  
pp. 855-858
Author(s):  
Glen M Shue
Keyword(s):  
Vitamin D ◽  
Collaborative Study ◽  
Internal Standard ◽  
High Potency ◽  
Chemical Evaluation ◽  
Accuracy And Precision ◽  
Chemical Assay ◽  
Color Reagent ◽  
Colorimetric Procedure ◽  
Better Than

Abstract Examination of data obtained from the 1963 collaborative study of a proposed chemical assay of vitamin D shows the following: the vitamin D content of the sample may be calculated by vising a reading at 550 mμ as the blank, with an accuracy and precision equal to or better than that of the proposed calculation; an internal standard is not necessary. These findings suggest a simplified colorimetric procedure which requires less than 5 μg (200 units). Data demonstrate a marked improvement in the color reagent resulting from reduction of the concentration of antimony trichloride. Preliminary data indicate that the method can be applied to high potency irradiated yeast.

Ferrozine iron and total iron-binding capacity method adapted to the ABA-100 Bichromatic Analyzer.

1981 ◽  
Vol 27 (8) ◽  
pp. 1441-1444 ◽  
Author(s):  
L Mori ◽  
A Bekkering ◽  
J Traini ◽  
L Vanderlinden
Keyword(s):  
Binding Capacity ◽  
Magnesium Carbonate ◽  
Total Iron ◽  
Iron Binding ◽  
Total Iron Binding Capacity ◽  
Standard Curve ◽  
Excess Iron ◽  
Color Reagent ◽  
Iron Binding Capacity ◽  
Capacity Method

Abstract A sensitive method (Clin. Chem. 26: 327--331, 1980) for serum iron, in which the color reagent Ferrozine is used, is modified and adapted to the Abbott ABA-100 discrete analyzer. The standard curve is linear to at least 10 mg/L and the method showed day-to-day precision (CV) of 2.4% for a 1.03 mg/L sample (n = 63) and 1.9% for a 2.13 mg/L sample (n = 63). Lower values were obtained than with the modified continuous-flow technique of Giovanniello et al., but the correlation was good (r = 0.98). Bilirubin and copper do not interfere; hemoglobin and gross lipemia interfere only slightly. The total iron-binding capacity, based on Ramsay's method, was evaluated with regard to the effect of adding various amounts of magnesium carbonate. Results led us to use a ratio of approximately 180 mg of magnesium carbonate to each 5 micrograms of excess iron added. Day-to-day, the method for total iron-binding capacity gave a CV of 3.1% for a 2.55 mg/L sample, 2.8% for a 3.63 mg/L sample.

A simple extract of Leucaena leucocephala (Lam.) de Wit leaf containing mimosine as a natural color reagent for iron determination

2021 ◽  
Vol 162 ◽  
pp. 105860
Author(s):  
Narong Kotchabhakdi ◽  
Chalermpong Seanjum ◽  
Kanokwan Kiwfo ◽  
Kate Grudpan
Keyword(s):  
Leucaena Leucocephala ◽  
Iron Determination ◽  
Natural Color ◽  
Color Reagent

Use of an Anion-Exchange Column to Determine Serum Iron-Binding Capacity

1971 ◽  
Vol 17 (9) ◽  
pp. 941-947 ◽  
Author(s):  
H Peter Lehmann ◽  
Alex Kaplan
Keyword(s):  
Serum Iron ◽  
Binding Capacity ◽  
Ferric Citrate ◽  
Iron Binding ◽  
Resin Column ◽  
Anion Exchange Column ◽  
Excess Iron ◽  
Colorimetric Measurement ◽  
Color Reagent ◽  
Iron Binding Capacity

Abstract A rapid procedure is described for determining total iron-binding capacity (TIBC) by use of a small, disposable resin column. Serum is saturated with excess ferric citrate, and iron not bound to protein is then removed by passing the mixture through the column of anion-exchanger. Transferrin-bound iron in the effluent, the TIBC, is determined colorimetrically (AutoAnalyzer), with 2,4,6-tripyridyl-1,3,5-triazine as color reagent. The percentage saturation with iron may be obtained from colorimetric measurement of original serum iron and the TIBC, or by radioactive counting if 59Fe is incorporated in the ferric citrate used to saturate the serum. Our method is compared with the MgCO3 precipitation technique for the removal of excess iron after saturation and to an ultrafiltration technique in which protein-bound iron is retained by a membrane and the filtrate analyzed for unbound iron, thus obviating absorbents in the determination of TIBC. Results from the resin-column and ultrafiltration procedures correlated well, whereas those from the MgCO3 method were consistently lower and more erratic.

Influence of monoclonal immunoglobulins in direct determinations of iron in serum

1991 ◽  
Vol 37 (5) ◽  
pp. 690-694 ◽  
Author(s):  
A J Bakker
Keyword(s):  
Serum Iron ◽  
Reference Method ◽  
Low Concentrations ◽  
Monoclonal Immunoglobulins ◽  
Color Reagent ◽  
Triton X

Abstract I compared seven buffers and four chromogens for determining serum iron, to evaluate the frequency of falsely high or low concentrations of iron in 59 sera containing monoclonal immunoglobulins. The results for these direct assays with untreated sera were compared with those obtained by a proposed reference method (Br J Haematol 1978;38:291-4) with protein-free filtrates of the same sera. Sera with monoclonal immunoglobulins sometimes yielded erroneous results; the frequency of errors, which could be as much as 29% (17/59), depended on the composition of buffer and color reagent. Addition of thiourea or a detergent (Triton X-405) to some of the buffers lowered the frequency of errors, but did not abolish them. In only a few of the investigated buffer/chromogen combinations were no errors found. Detection of errors by analyzing the absorbance pattern after mixing sample and buffer was not always successful. Moreover, the presence and magnitude of errors bore no relationship to the type or the concentration of the monoclonal immunoglobulins. Unfortunately, the problem cannot be solved by a simple two- or threefold dilution of the sample.

Sign in / Sign up

Export Citation Format

Share Document