Sensitive visual and micro spectrophotometric methods have been developed for field determination of trace iron in fresh water samples. For the visual method, a water sample (0.45-microm filtrate acidified to 0.1 M HCl) was placed in a glass vial and mixed with a reagent solution containing 1,10-phenanthroline, sodium thiocyanate and 0.1 M HCl. Iron was extracted as pink ferroin thiocyanate wit...

Development of easy, practical, and low-cost spectrophotometric methods is required for the selective determination of phenolic antioxidants in the presence of other similar substances. As electron transfer (ET)-based total antioxidant capacity (TAC) assays generally measure the reducing ability of antioxidant compounds, thiols and phenols cannot be differentiated since they are both responsive...

During the investigation of aviation accidents, postmortem samples from accident victims are submitted to the FAA's Civil Aerospace Medical Institute for toxicological analysis. In order to determine if an accident victim was exposed to an in-flight/postcrash fire or faulty heating/exhaust system, the analysis of carbon monoxide (CO) is conducted. Although our laboratory predominantly uses a sp...

Inland waters have an important role in the global carbon cycle, contributing significantly to terrestrial fluxes through downstream export and exchange of CO2 with atmosphere. However, large uncertainties freshwater inorganic remain. One factor is uncertainty carbonate system calculations for estimating partial pressure (pCO2) from pH alkalinity systems. The stems largely inaccurate values cau...

This study examined the role of self-monitoring support for writing skill improvement in a reciprocal peer review of writing system called SWoRD (Cho & Schunn, 2007). Because self-monitoring has been identified as a critical component in self-regulated learning (Butler & Winne, 1995; Cresswell, 2000; Zimmerman & Risemberg, 1997), students were provided with opportunities to self-monitor their w...

A simple, sensitive and economically viable spectrophotometric method for the determination of corticosteroids (predinsolone {PSL}, dexamethasone {DEX}, prednisone {PS}, betamethasone sodium phosphate {BEP} and hydrocortisone {HYD} has been developed. The method involves the oxidation of corticosteroids by iron (III) and subsequent complexation of iron (II) with potassium hexacynoferrate (III),...

partial least squares modeling as a powerful multivariate statistical tool was applied tothe simultaneous spectrophotometric determination of silicate and phosphate in aqueoussolutions. the concentration range for silicate and phosphate were 0.02-0.6 and 0.4-3 μg ml-1,respectively. the experimental calibration set was composed with 30 sample solutions using amixture design for two component mix...

Full Text PDF. Recovery studies were performed using 0. 5 mL of red wine and whisky. Enter the password to open this PDF file. spectrophotometric determination of ethanol in wine pdf Treatment procedures, and only spectrophotometry is used1 Jan 2012. The method consists of color reaction of ethanol with sodium dichromate. SPECTROPHOTOMETRIC DETERMINATION. For spectrophotometric determination of...

In this study, the development of an indirect spectrophotometric method for determination folic acid in pure and pharmaceutical preparations is described. The based on oxidation pyrocatechol with iron (III) acidic medium, followed by reaction (FA) to produce a stable, water-soluble orange compound maximum absorption at 350 nm versus blank reagent. complex charge transfer was studied under optim...