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Victor Meyer (1848-1897) was one of the most outstanding chemist of the second half of the 19th century. He is known for his numerous papers in the field of organic chemistry. The purpose of this paper is to familiarize readers with the important events in the life of Meyer. In addition, his research activities is briefly described, and especially the chemical reaction named after him

Frederick Soddy (1877-1956) was the most prominent chemists of the first half of the 20th century. He is known for his numerous papers in the field of radiochemistry. He was the laureate of the Nobel Prize in Chemistry for 1921. The purpose of this paper is to familiarize readers with the important events in the life of Soddy and his research activities, in particular with selected results of his experimental studies as well as with his selected publications. In addition, his writing activity was described, in particular his books, well known in various countries, were presented.

Paul-Émile (François) Lecoq de Boisbaudran (1838-1912) was an important French chemist in the second half of the XIX century and the first decade of the XX century. He was one of the founders of spectroscopy. He discovered gallium (1875), samarium (1879), and dysprosium (1886) and improved methods for the separation of rare earths elements. The purpose of this paper is to familiarize readers with the important events in the life of Lecoq de Boisbaudran and his great discoveries. In addition, literature on his selected papers and books, as well as literature on his chapters in books is presented

Carl Schorlemmer (1834-1892), the first professor of organic chemistry in the Owens College, Manchester (and in England), was the prominent Anglo-German chemist and historian of chemistry of the second half of the 19th century. He studied the constitution of paraffinic hydrocarbons. The purpose of this paper is to familiarize readers with the important events in the life of Schorlemmer and his research activities and writing, in particular some of his experimental results, as well as his selected publications.

Ira Remsen (1846-1927) was one of the great American chemists. He carried out his experimental studies in the field of organic chemistry. In 1879, he became a co-discoverer of saccharin. He was the first professor of chemistry (1876-1901) and the second president (1901-1913) of the Johns Hopkins University in Baltimore. The purpose of this paper is to familiarize readers with the important events in the life of Remsen and his writing activities, in particular with his chemistry textbooks, well-known in various countries. In addition, literature on his selected articles is presented

Richard Anschütz (1852-1937) was an important German chemist in the second half of the XIX century and the first quarter of the XX century. He carried out experimental studies in the field of organic chemistry. He proposed a new method for the synthesis of anthracene. He developed vacuum distillation. He prepared pure chloroform. He rescued the names of Archibald Scott Couper (1831-1892) and Joseph Loschmidt (1821-1895) from oblivion. The purpose of this paper is to familiarize readers with the important events in the life of Anschütz. In addition, literature on his selected articles and books is presented.

Ernst Julius Cohen (1869-1944) was an outstanding Dutch chemist and historian of chemistry of the second half of the XIX century and the first half of the XX century. He contributed to the fields of polymorphism, thermochemistry, electrochemistry and piezochemistry. He also studied physical isomerism. His experimental studies on allotropy has been published in a large number of publication. The purpose of this paper is to familiarize readers with the important events in the life of Cohen and his research activities, in particular with his selected publications as well as with his writing activities, in particular with his books

Adolf von Baeyer (1835-1917) was the most prominent chemists of the second half of the 19th century and the early part of the twentieth century. He is known for his many works in the field of organic chemistry. He was the first to synthesize indigo. He was awarded the Nobel Prize in Chemistry in 1905. The purpose of this paper is to familiarize readers with the important events in the life of Baeyer and his research activities, in particular with selected results of his experimental studies as well as with his selected publications. In addition, literature on his correspondence is given

Sir Thomas Edward Thorpe (1845-1925) was one of the most prominent chemists of the second half of the 19th century. He studied phosphorus oxides and fluorine compounds. He is known for his works on the determination of the atomic weights of chemical elements and for his books on chemistry and the history of chemistry. The purpose of this paper is to familiarize readers with the important events in the life of Thorpe and his writing and research activities, in particular some of his experimental results, as well as his selected publications

Edgar Fahs Smith (1854-1928) was one of the great American chemists. He has done a lot of experimental studies. He carried out researches in the fields of organic, inorganic, and analytical chemistry, elektrochemistry and mineralogy. He developed the rotating anode. He wrote many works in the field of history of American chemistry. The purpose of this paper is to familiarize readers with the important events in the life of Smith. In addition, his participation in the preparation of the first visit of Marie Curie (1867-1934) to the USA in 1921 is described and literature on his selected articles and books is presented

Clemens Alexander Winkler (1838-1904) was one of the prominent chemists of the second half of the XIX century. He was the founder of technical gas-analysis. He made major contributions both to pure and applied chemistry. He also developed a contact method for the production of sulfuric anhydride (sulfur trioxide) and discovered Germanium. The purpose of this paper is to familiarize readers with the important events in the life of Winkler and his research activities, in particular with his selected publications as well as with his writing activities, in particular with his books. In addition, literature on his correspondence with some great chemists is given

Adolf von Baeyer (1835-1917) was the most prominent chemists of the second half of the 19th century and the early part of the twentieth century. He is known for his many works in the field of organic chemistry. He was the first to synthesize indigo. He was awarded the Nobel Prize in Chemistry in 1905. The purpose of this paper is to familiarize readers with the important events in the life of Baeyer and his research activities, in particular with selected results of his experimental studies as well as with his selected publications. In addition, literature on his correspondence is given.

Jean Antoine Chaptal (1756-1832) was one of the important chemists of the second half of the 18th century and the first half of 19th century. He wrote a number of works dealing with various branches of applied chemistry. The purpose of this paper is to familiarize readers with the important events in the life of Chaptal and his writing activities, in particular with his chemistry textbooks and books on applied chemistry, well-known in different countries. In addition, his research activities is briefly described

Hans Landolt (1831-1910) was one of the important chemists of the second half of the XIX century and the first decade of the XX century. The purpose of this paper is to familiarize readers with the important events in the life of Landolt and his writing activities, in particular with his chemistry books. In addition, his research activities is briefly described, and especially the chemical reaction named after him.

Sophus Mads Jørgensen (1837-1914) was one of the important chemists of the second half of the XIX century and the first decade of the XX century. He was one of the founders of the chemistry of complex compounds. He also made major contributions to the chemistry of platinum, cobalt, chromium and rhodium compounds. The purpose of this paper is to familiarize readers with the important events in the life of Jørgensen and his writing activities, in particular with his chemistry books. In addition, his research activities are briefly described

Thomas Edward Thorpe (1845-1925) was one of the most prominent chemists of the second half of the 19th century. He studied phosphorus oxides and fluorine compounds. He is known for his works on the determination of the atomic weights of chemical elements and for his books on chemistry and the history of chemistry. The purpose of this paper is to familiarize readers with the important events in the life of Thorpe and his writing and research activities, in particular some of his experimental results, as well as his selected publications

It is well - known that during aging, several compounds are extracted from the oak barrels that have a positive influence on the sensory characteristics of the rum. The sensory improvement is the re sult of many transformations that take place among the rum distillate components and those of the oak wood. These involve reactions between constituents of the spirit, reactions between substances extracted from the wood and their oxidation, and reactions between the original compounds, extracted compounds, and those formed previously. For the aging of Cuban rum in oak barrels it has been necessary to import it and there are lots of barrels with the origin known, but others unknown. This paper analyzed the profile of oak volatile compounds of three lots coming from American, former Soviet Union and Yugoslavia and three lots of unknown origin. With maceration of oak chips with ethanol 55% v/v, extraction with dichloromethane and gas chromatography - mass spectr ometry analysis, 126 volatiles compounds were determined including phenol derivatives (40), esters (28), acids (17), alcohols (11), terpenes (10), aldehydes and ketones (8), acetals (4), furanic derivatives (3), lactones (3), and others with different func tions (2). A total of 70 compounds showed statistical differences and the principal component and discriminant analysis classified the six lots in four groups: American, former Soviet Union and former Yugoslavia origin in different groups, two unknown orig in lots in the same group with Yugoslavian lot and a remaining lot of unknown origin in a separate group

It is well-known that during aging, several compounds are extracted from the oak barrels that have a positive influence on the sensory characteristics of the rum. The sensory improvement is the result of many transformations that take place among the rum distillate components and those of the oak wood. These involve reactions between constituents of the spirit, reactions between substances extracted from the wood and their oxidation, and reactions between the original compounds, extracted compounds, and those formed previously. For the aging of Cuban rum in oak barrels it has been necessary to import it and there are lots of barrels with the origin known, but others unknown. This paper analyzed the profile of oak volatile compounds of three lots coming from American, former Soviet Union and Yugoslavia and three lots of unknown origin. With maceration of oak chips with ethanol 55% v/v, extraction with dichloromethane and gas chromatography-mass spectrometry analysis, 126 volatiles compounds were determined including phenol derivatives (40), esters (28), acids (17), alcohols (11), terpenes (10), aldehydes and ketones (8), acetals (4), furanic derivatives (3), lactones (3), and others with different functions (2). A total of 70 compounds showed statistical differences and the principal component and discriminant analysis classified the six lots in four groups: American, former Soviet Union and former Yugoslavia origin in different groups, two unknown origin lots in the same group with Yugoslavian lot and a remaining lot of unknown origin in a separate group.

Victor von Richter (1841-1891) was one of the important chemists of the second half of the 19th century. The purpose of this paper is to familiarize readers with the important events in the life of Richter and his writing activities, in particular with his chemistry textbooks for higher education, well-known in different countries. In addition, his research activities is briefly described, and especially the chemical reactions named after him.

Johan Gadolin (1760-1852), considered the father of Finnish chemistry, was one of the leading chemists of the second half of the 18th century and the first half of the 19th century. His life and scientific achievements were described in the literature published between the 19th and 21st centuries. The purpose of this paper is to familiarize readers with the important events in the life of Gadolin and his research activities, in particular some of his research results, as well as his selected publications. In addition, the names of authors of biographical notes or biographies about Gadolin, published in 1839-2017 are presented.

Charles-Adolphe Wurtz (1817-1884) was an outstanding French chemist of the second half of the the XIX century. He was one of the founders of of modern organic chemistry. He discovered many organic compounds. The purpose of this paper is to familiarize readers with important events in the life of Wurtz and his writing activities, in particular with the literature on his books in the field of chemistry and biochemistry. In addition, the literature on selected works is presented and the chemical reactions named after him are described.

In this paper, cocaine and eleven of its metabolites have been detected and identified in urine samples. The technique was based in a simple liquid-liquid extraction with detection by gas chromatography coupled to mass spectrometry (GC-MS). The method was validated in terms of repeatability, specificity, recovered, linearity, limit of detection, contamination between samples and robustness, all validation parameters met the acceptance criteria established in the study. The percentages of recovered for cocaine and benzoylecgonine were 120 and 110% respectively. The method’s repeatability (CV %) remained below 15% in all assays. The technique was shown to be linear over the range studied (r2 = 0.999) and sensitive, with detection limits below 60 ng/mL for both analytes. In the analysis of two real samples 11 metabolites of cocaine were detected, benzoylecgonine and cocaetilene were the majorities. Furthermore, were detected and characterized metabolites which only are observed in the urine in overdose cases such as hydroxylated and metoxyhydroxylated metabolites of cocaine, benzoylecgonine and cocaethilene. The technique allowed detecting the cinnamoilbenzoilecgonina which is a metabolite of cinnamoilcocaína. The cinnamoilcocaína is one of the alkaloids in coca plants so the presence of this metabolite showed us natural cocaine consumption and not synthetic.

Cymbopogon citratus (D.C.) Stapf., commonly known as lemongrass or “hierba luisa”, is widely cultivated in many tropical and subtropical regions due to its aromaticand medicinal properties. The essential oil from leaves has many pharmacological activities reported. The present paper reports the chemical composition and the antioxidant and antimicrobial activities of the essential oil of leaves from plants grown in the Amazonian Ecuador. The essential oil was obtained by steam distillation. Analyses of the essential oil were performed by gas chromatography with flame ionization and mass selective detectors. Seventy compounds were identified in the essential oil. Oxygenated compounds were the most represented class of volatiles (86%), including neral (33.2 %) and geranial (39.8 %) as major compounds. Monoterpene hydrocarbons were the second class (10.7 %) with myrcene (9.6 %) as predominant. Antioxidant properties of the essential oil were determined by ABTS and FRAP methods. The essential oil had a low radical-scavenging activity and it showed ferric reducing capacity, while it has antimicrobial activity against Staphylococcus aureus and Salmonella Enteritidis, followed by E.coli and very low against Bacillus subtilis, Aspergillus niger and Pennicilium citrinum.

Turmeric (Curcuma longa L.) is a rhizomatous herbaceous perennial plant widely cultivated in the tropical and subtropical regions of the world. The essential oil from rhizomes has many pharmacological activities reported. The present paper reports the chemical composition and the antioxidant and antimicrobial activities of the essential oil from rhizomes grown in the Amazonian Ecuador. The essential oil was obtained by steam distillation. Analyses of the essential oil were performed by gas chromatography with flame ionization and mass selective detectors. Eighty-eight compounds were identified in the essential oil. Oxygenated compounds were the most represented class of volatiles (63.6%), including ar-turmerone (45.5%) and α-turmerone (13.4%) as major compounds. Sesquiterpene hydrocarbons were the second class (18.0%) with α-zingiberene (5.3%) as predominant. Another major constituent was the monoterpene hydrocarbon α-phellandrene (6.3%). Antioxidant properties of the essential oil were determined by radical-scavenging capacity of the oil (DPPH) and ferric-reducing antioxidant power (FRAP) methods. The essential oil had a low antioxidant activity by both methods, while it has antimicrobial activity against gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Pennicilium citrinum. No antimicrobial activity was found against Escherichia coli, Salmonella Enteritidis and Aspergillus niger.