This paper contemplates the scientific contributions of the seven winners, from the creation of the Nobel Prize to the year 2020. The laureates are Marie Curie, Irène Joliot-Curie, Dorothy Crowfoot Hodgkin, Ada Yonath, Frances Hamilton Arnold, Emmanuelle Marie Charpentier, and Jennifer Anne Doudna. In 112th editions of the Nobel Prize in Chemistry, there were 186 awards, where only seven winners were women, an amount less than 4% of the total, which makes clear the low female representation. Marie was the pioneer, being the first woman to win, alone, a Nobel Prize in Chemistry. She was the only woman to win two Nobel Prizes, and the only person awarded in two distinct scientific areas: Chemistry and Physics. Only Marie and Dorothy received the award alone, Irène, Ada and Frances shared the award with men, and Emmanuelle and Jennifer became the first pair of women to share a Nobel Prize in Chemistry. There is an evident under-representation of women in the Nobel Prize in Chemistry, but this should not be a reason not to remember and celebrate the trajectory of these brilliant scientists, who must be present in training courses in scientific areas, as well as in Basic Education schools.

Natural deep eutectic solvents (NADES) based on xylitol, citric acid, and malic acid were synthesized and used in ultrasound-assisted extraction (UAE) and heating-bath extraction of phosphate rock and mineral supplement samples. Arsenic, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP OES). The results showed the NADES as promising solvents for extraction of inorganic matrices compared to reference values and concentrations obtained using microwave-assisted acid digestion (MW-AD). Significant differences were observed for some elements, suggesting different chemical interactions between the synthesized NADES and each monitored element. For analytes extraction of phosphate rock, UAE presented the best results for As, Cr and P. Zinc was extracted with UAE and heating bath. Concerning mineral supplement, no significant differences were observed for Ca (UAE), Cd (UAE and heating bath), K (UAE and heating bath), Mn (UAE and heating bath), Na (UAE and heating bath), and P (UAE and heating bath). The NADES is a greener and a potentially alternative for the sample preparation compared to the official methods of analysis, can being used as selective extractor solvent in conventional sample preparation methods.

This work aimed the development of an analytical procedure using inductively coupled plasma mass spectrometry (ICP-MS) in four modes of operation for simple and fast determination of Al, Ag, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Li, Mg, Mn, Na, Ni, Pb, Sb, Se, Tl, Hg, V, U, and Zn in fresh and sea water samples attending simultaneously four Brazilian regulations, Ordinance No. 2914, ANVISA No. 274 and CONAMA Nos. 357 and 396. High matrix introduction system enables the introduction of sea water (3.5% m v-1 of NaCl) only 2-fold diluted. Collision cell mode was efficient to overcome polyatomic interferences. The procedure presented limits of detection (LODs) lower than maximum concentrations allowed by regulations. The CRM NIST 1643e and addition-recovery experiments were used to check accuracy and recoveries varied from 84 to 115%. ICP-MS combined with collision cell mode and aerosol dilution led to accurate and simultaneous determinations of 25 elements at different concentration levels in samples containing high contents of total dissolved solids.

Determination of Se by inductively coupled plasma mass spectrometry (ICP-MS) can be difficult due to spectral interferences; however, these interferences can be eliminated by using collision-reaction interface (CRI) technology. A simple and fast procedure for determination of total Se concentration in bovine semen by ICP-MS after sample solubilization with diluted formic acid is here proposed. Formic acid caused an increase of up to 50% in selenium net signals and the maximum gain was obtained at 10% v v-1 formic acid solution. The optimized nebulizer gas flow rates were 1.05 and 0.95 L min-1, and radio frequency applied power were 1.3 and 1.4 kW without and with CRI, respectively. Microwave-assisted acid digestion was also implemented in the preparation of semen sample for comparison of results. No statistical differences between these sample preparation strategies at 95% confidence level (t-test) were observed for 76Se+, 77Se+, 78Se+ and 82Se+ without using CRI and 82Se+ with CRI.

Inorganic elements present in pharmaceutical products were determined by inductively coupled plasma-mass spectrometer (ICP-MS), employing microwave acid digestion as a sample preparation method. The most abundant isotopes, 75As+, 65Cu+, 52Cr+, 58Ni+, 208Pb+, and 51V+, were determined in acyclovir ointment and its constituents. Elemental impurities in the pharmaceutical samples were determined using an inductively coupled plasma-universal cell technology-mass spectrometer (ICP-UCT-MS) operated in kinetic energy discrimination (KED) and standard mode. The accuracy of the method was assessed by means of addition and recovery experiments. Except for Cr, spiked recoveries of the elements added to the samples before microwave acid digestion (MW-AD) step were between 95.1 and 126%, and after MW-AD step ranged from 85.6 to 132%. Limits of detection (LOD) obtained by proposed method is in agreement to those required by the U.S. Pharmacopeia Convention (USP), showing that the ICP-MS technique is well suited for quantification of these elements. The LOD's (ng L-1) for 51V+, 52Cr+, 58Ni+, 65Cu+, 75As+ and 208Pb+ in 1% v v-1 HNO3 medium were: 2.2, 81.3, 91.9, 6.9, 0.2 and 3.1, respectively. The concentration of the analytes in these samples presented a wide range, varying from 2.3 ± 0.8 µg kg-1 for As to 3446 ± 47 µg kg-1 for Cr.

In the present work, an inductively coupled plasma-tandem mass spectrometer (ICP-MS/MS) operating in single quadrupole and mass shift modes were evaluated for As determination in mineral fertilizers and agricultural gypsum with high contents of rare earth elements. For MS/MS mode, oxygen was the gas introduced into the octopole reaction system (ORS3). Samples were prepared by microwave-assisted digestion with diluted nitric acid solution. The accuracy was checked by analysis of a fertilizer certified reference material (NIST SRM 695) and by addition and recovery experiments. When operating in single quadrupole mode, recoveries ranged from 59 to 151%; while values obtained by MS/MS mode varied from 81 to 105% when 0.30 mL min-1 O2 was introduced into the ORS3. Limits of detection for As+ in single quadrupole and AsO+ in MS/MS mass shift mode were 6 and 9 ng L-1, respectively.