James Moir (1874–1929) Pioneering Chemical Analyst in South Africa in the Early 1900s

James Moir, a pioneering chemist in SouthAfrica, played a leading role in the SA Chemical Institute. He was an excellent organic chemist, who published widely on the relationship between the colour of an organic substance and its chemical structure. In addition to this, he worked as an analyst in the  Government Chemical Laboratories in Johannesburg, where he was exposed to a wide variety of chemical analyses. He developed many new methods of analysis and improved others, which he published in the official journal of the Chemical Institute. This article traces his chemical analysis research work as  gleaned from the pages of this journal. It deals with coal analysis, where he developed a simple formula to predict the calorific value, determination of nitrous fumes in air with special reference to fuse-igniters, improving the structure of methyl orange as an indicator, analysis of metals such as Cu, Co, As and Cr, and cyanide analysis. Furthermore, the article discusses his sensitive test for phenol and gives a case study where he did some chemical detective work. From all of this, it is apparent that James Moir was a very fine analyst. He is commemorated by  Chemistry students for the ‘James Moir Medal’, awarded annually to the top BSc (Hons) or BTech student at South African universities.KEYWORDS:Analysis, early 1900s, education, pioneering chemist, SACI

James Moir as Inorganic Chemist

James Moir was a pioneering chemist in the early 1900s who played a leading role in various chemical societies in South Africa. Although he was mainly an organic chemist, he also made contributions in the field of inorganic chemistry. His forays in this field deal with gold extraction using the new solvent thiourea, removal of cyanide using ferrous sulphate, and investigations into the ‘purple of Cassius’. He was also a theoretical chemist who played a role in the development of atomic theory and made suggestions to help unravel the nature of the atom, the composition of the nucleus and chemical combination.KEYWORDS: Inorganic chemistry, gold, atomic theory, history of chemistry

James Moir as Organic Chemist

James Moir played a leading role in the South African Chemical Institute and was a pioneering organic chemist in South Africa during the early 1900s. He published widely on various organic topics but was especially noted for his work on the relationship between the colour of an organic substance and its chemical structure or constitution.After some initial research work in Scotland and London dealing with amarine and diacetonitrile, he arrived in South Africa in 1902. He first worked on derivatives of diphenol, oxidation products of benzidine, diphenylquinone and other compounds. His immense study of colour covered the years 1916–1929. He put forward theories on colour, which he applied to a whole range of phthaleins and related compounds, in order to see the effect of substitution on the spectrumof the compound. He introduced his numerical solution of colour, by which he could predict the band centre of absorption of many compounds. He applied this to a variety of different dyes and substituted products of phenolphthalein and fluorescein, relating colour to structure. He also studied the factors responsible for organic fluorescence, and doubly-linked diphenylene compounds. Finally he studied the structure of various flower pigments. This article explores his research output in the field of organic chemistry.KEYWORDS: Colour, phthaleins, history of chemistry, organic chemistry

The Contributions of James Moir to Physical Chemistry

James Moir was a pioneering chemist in the early 1900s who played a leading role in various chemical societies in South Africa. Although he was mainly an organic chemist, he was a very good all-round chemist, whose analytical and organic activities have already been covered in this journal. This article examines his research in physical chemistry, covering the spectral analysis of the ruby and emerald gemstones, a detailed analysis of part of the Fraunhofer lines of the solar spectrum, and an examination of the spectra of cobalt compounds, the permanganate ion, and uranium compounds. Finally, as part of his inorganic and analytical investigations, he also delved into the physical chemistry aspects of solution chemistry, particularly the hydrolysis of the cyanide ion.KEYWORDS :Physical chemistry, spectroscopy, ruby, solar spectrum, history of chemistry

Mechanistic and Kinetic Aspects of the Direct Electrochemical Oxidation of 4-t-Butyltoluene

The direct electrochemical oxidation of 4-t-butyltoluene at graphite electrodes in methanol, using NaClO4 as electrolyte, as been investigated in order to obtain an insight into the mechanism and kinetics of the anodic reactions taking place. It is shown that an increase in current density affects the product distribution, leading to a better yield of the target product 4-t-butylbenzaldehyde dimethyl acetal and a lower percentage of unknowns at the expense of an increase in electrical charge. It is suggested that oxidation takes place by two mechanisms : a direct one involving oxidation of the substrate at the electrode, and an indirect one where a pool of solvent radicals assists in the oxidation process. Further evidence is provided for reaction mechanisms in studies where the substrate loading is varied, and also where the ratio of substrate to solvent is varied ; when the concentration of the substrate is high, there is evidence of the formation of dimers and other unknowns. Under certain conditions, these anodic reactions can be regarded as parallel consecutive second order reactions. The role played by the solvent is confirmed by kinetic data. South African Journal of Chemistry Vol.55 2002: 125-13

Incidence of medication-related osteonecrosis of the jaw in patients treated with both bone resorption inhibitors and vascular endothelial growth factor receptor tyrosine kinase inhibitors

Background: Several case reports and small case series have suggested a higher incidence of medication-related osteonecrosis of the jaw (MRONJ) in patients treated concomitantly with bone resorption inhibitors (BRIs) and vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs), as compared to patients treated with BRIs alone. We aimed to assess ONJ-incidence in patients exposed concomitantly to BRIs and VEGFR-TKIs. Patients and methods: We reviewed the records of all patients who received VEGFR-TKIs concomitantly with BRIs. Patients, who were treated with BRIs without VEGFR-TKI, served as a control group. Endpoints of the study were total MRONJ-incidence, MRONJ-incidence during the first and second year of exposure, and time-to-ONJ-incidence. Results: Ninety patients were treated concomitantly with BRIs and VEGFR-TKIs with a median BRI-exposure of 5.0 months. Total MRONJ-incidence was 11.1%. During the first year of BRI-exposure (with a median concomitant exposure of 4.0 months), 6 out of 90 patients (6.7%) developed a MRONJ, compared to 1.1% in the control group (odds ratio 5.9; 95%CI 2.0–18.0; p = 0.0035). In Kaplan-Meier estimates, time-to-ONJ-incidence was significantly shorter in patients treated with BRIs and VEGFR-TKIs compared to BRIs alone (hazard ratio 9.5; 95%CI 3.1–29.6; p < 0.0001). MRONJs occurred earlier in patients treated concomitantly compared to patients treated with BRIs only (after a median exposure of 4.5 and 25.0 months, respectively; p = 0.0033). Conclusion: With a global MRONJ-incidence of 11%, patients receiving concomitant treatment with VEGFR-TKIs and BRIs have a five to ten times higher risk for development of MRONJ compared to patients treated with BRIs alone