There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Statistics for analytical chemistry

In situ chemical oxidation of a carbamazepine solution was performed using persulfate anions simultaneously activated by heat energy (thermal, ultrasound), UV-C light, Fe2+ ions, and hydrogen peroxide. The main objective of this study was to analyze the mineralization reactions that occurred during the studied operating conditions. Solution TOC removal was nearly complete (99%) within 90 min, which prevented the accumulation of toxic intermediates. The mineralization process of carbamazepine solutions can be described using pseudo-second-order kinetics. Under acidic conditions, Fe2+ can exhibit catalytic effects on H2O2 decomposition and persulfate activation. With excess persulfate, an unproductive S2O82− decomposition reaction (with no generation of SO4 −) or a rapid reaction between excess sulfate radicals to produce sulfate anions could occur. Sulfate and hydroxyl radicals were involved in the main mineralization pathway. The influences of chloride ions on mineralization were also evaluated. The results demonstrated that this activated persulfate-based oxidation system could be used to control water pollution by emerging contaminants, such as carbamazepine.

In situ chemical oxidation of carbamazepine solutions using persulfate simultaneously activated by heat energy, UV light, Fe2+ ions, and H2O2

Chemometrics: A Textbook

Occurrence, interactive effects and ecological risk of diclofenac in environmental compartments and biota - a review

The use of derivative UV-spectrophotometry is proposed for the simultaneous quantification of promazine hydrochloride in the presence of sulfoxide, and vice versa. For this purpose, mathematical parameters were established for generating derivative spectra of analytes. The determination of promazine was made using the first-order derivative (deltalambda = 10 nm, second polynomial degree) at 268 nm. The quantification of sulfoxide was achieved by applying third-derivative spectra (deltalambda = 14 nm, sixth polynomial degree) based on measurements of the amplitude at 342 - 344 nm. An elaborated method was successfully used to determine analytes in commercial promazine pharmaceuticals. The obtained results agreed well with those obtained by the HPLC method.

Simultaneous quantification of promazine hydrochloride and its sulfoxide in pharmaceutical preparations.

2,10-Disubstituted phenothiazines are the best drugs in psychiatry Several methods for their analysis have been reported in the literature The official methods are based on non-aqueous titration or spectrophotometry Various oxidizing agents have been used for the spectrophotometric determination of 2,10-disubstituted phenothiazines, eg Ce(SO4)2, NH4VO3, K2S208, KIO4, KIO3, KBrO3, FeCl3, NaNO2, H2O2, chloramine T, p-benzoquinone, N-bromosuccinimide Oxidation reactions of phenothiazines were also used for their determination by flow-injection methods

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Efficient Oxidizing Agents for Determination of 2,10-Disubstituted Phenothiazines

This study shows the results of application liquid chromatography-tandem mass spectrometry (LC/MS/MS) for assay of the content of α-tocopherol and coenzyme Q10 in bee products of animal origin, i.e. royal jelly, beebread and drone homogenate. The biological matrix was removed using extraction with n-hexane. It was found that drone homogenate is a rich source of coenzyme Q10 . It contains only 8 ± 1 µg/g of α-tocopherol and 20 ± 2 µg/g of coenzyme Q10 . The contents of assayed compounds in royal jelly were 16 ± 3 and 8 ± 0.2 µg/g of α-tocopherol and coenzyme Q10 , respectively. Beebread appeared to be the richest of α-tocopherol. Its level was 80 ± 30 µg/g, while the level of coenzyme Q10 was only 11.5 ± 0.3 µg/g. Copyright © 2016 John Wiley & Sons, Ltd.

LC/MS/MS analysis of α-tocopherol and coenzyme Q10 content in lyophilized royal jelly, beebread and drone homogenate.

The application of the Vierordt's method and derivative spectrophotometry for simultaneous determination of amitryptyline (AMT) and chlorpromazine (CPM) hydrochlorides in their binary mixtures are presented. Both methods allow to determine the components without their isolation. By derivative spectrophotometry, amitryptyline hydrochloride can be determined in the range of 2–15 μg/ml and chlorpromazine hydrochloride between 2–53 μg/ml. The acceptable error was obtained when the ratio analyte:second component ranges from 3:1 to 50:1 for amitryptyline and 0.1 : 1–0.8 : 1 for chlorpromazine. The Vierordt's method can be applied for resolution of the studied mixture when the ratio analyte : second component is in the 3:1–45:1 and 11:1–57:1 range for amitryptyline and chlorpromazine, respectively.

The spectrophotometric simultaneous determination of amitryptyline and chlorpromazine hydrochlorides in their binary mixtures

The article discusses analytical problems related to the determination of coenzyme Q10 in biological samples The assaying of coenzyme Q10 in complex samples, such as plasma, tissues, or food items requires meticulous sample preparation prior to final quantification The process typically consists of the following steps: deproteinization, extraction, and ultimately reduction of extract volumes At times drying under a gentle stream of neutral gas is applied In the case of solid samples, a careful homogenization is also required Each step of the sample preparation process can be a source of analytical errors that may lead to inaccurate results The main aim of this work is to point to sources of analytical errors in the preparation process and their relation to physicochemical properties of coenzyme Q10 The article also discusses ways of avoiding and reducing the errors

Joanna Karpińska

Papers

Simultaneous quantification of promazine hydrochloride and its sulfoxide in pharmaceutical preparations.

Efficient Oxidizing Agents for Determination of 2,10-Disubstituted Phenothiazines

LC/MS/MS analysis of α-tocopherol and coenzyme Q10 content in lyophilized royal jelly, beebread and drone homogenate.

The spectrophotometric simultaneous determination of amitryptyline and chlorpromazine hydrochlorides in their binary mixtures

Analytical problems with the determination of coenzyme Q10 in biological samples