This work proposes the reuse of spent ground coffee waste (SCG) extracts as eco-friendly corrosion inhibitors for carbon steel in acid medium, and the correlation between their anticorrosive efficiency and chemical composition. The extraction method was optimized using a central composite design, and the chemical composition of the extracts was accessed using UV-Vis spectrometry, HPLC, and ICP-OES. EIS and Potentiodynamic Polarization (PP) tests evaluated the anticorrosive properties of the extracts. Total phenol content ranged from 93 mg L-1 to 219 mg L-1 Gallic Acid Equivalent. The highest concentration of phenolic compounds was observed for syringic acid (78.67 mg L-1), while the lowest concentration was verified for (-)-epigallocatechin-3-O-gallate (0.01 mg L-1). The Pearson correlation coefficient showed no correlation between the Rct and the total phenol content, although, positive correlations with the Rct was observed for caffeic acid, (+)-catechin, ferulic acid, and protocatechuic acid. EIS analysis revealed that all of the extracts could act as corrosion inhibitors. The best performance was verified for C3 extract (IE % = 94.83%). PP tests showed that this extract acted as a mixed inhibitor, with a predominant cathodic effect. Therefore, the valorization of the extracts as corrosion inhibitors was successfully achieved.

Um método para a determinação de traços de Pb em ossos por espectrometria de absorção atômica é descrito. Boas precisão e exatidão foram obtidas utilizando-se calibração externa com padrões aquosos e NH4H2PO4 como modificador. O limite de detecção alcançado foi de 0,07 ng mL-1 na solução de leitura, correspondendo a 0,022 mg g-1 na amostra original. Conseqüentemente, o limite de quantificação encontrado foi de 0,23 ng mL-1. Uma precisão de 3,5% foi obtida na leitura de 400 ng de Pb na presença da matriz. A exatidão do procedimento foi confirmada pela boa concordância entre os valores certificado e encontrado na análise de um material certificado de referência (NIST SRM 1846, bone meal).

A simple method for measuring trace levels of Pb in bone by electrothermal atomic absorption spectrometry is described. It is shown that Pb can be accurately measured with good precision and accuracy using external calibration with aqueous Pb analytical solutions containing NH4H2PO4 as modifier. The detection limit was found to be 0.07 ng mL-1, corresponding to 0.022 mg g-1 in the original sample. Consequently, the limit of quantification was found to be 0.23 ng mL-1. The precision of the procedure, expressed by the relative standard deviation, was 3.5% for 400 ng Pb in sample measurements. The accuracy of the procedure was confirmed by the good concordance between found and certified values in the analysis of a bone meal certified reference material, NIST SRM 1846.

A basic investigation into the removal of copper ions from aqueous solutions by Sargassum sp. was conducted in batch conditions. The influence of different experimental parameters such as initial pH, shaking rate, sorption time, temperature, equilibrium conditions and initial concentrations of copper ions on copper uptake was evaluated. Results indicated that for shaking rates higher than 100 rpm no significant changes in copper accumulation were observed, as well as for pH values between 3.0 and 5.0. No marked effect on the biosorption of copper was detected for temperatures between 298 and 328K. The Langmuir model better represented the sorption process, in comparison to the model of Freundlich. The process followed a second-order kinetics and its calculated activation energy was 5.2 kcal/mol. Due to its outstanding copper uptake capacity (1.48 mmol/g biomass) Sargassum sp. proved to be an excellent biomaterial for accumulating and recovering copper from industrial solutions.

The historical development of atomic spectrometry techniques based on chemical vapor generation by both batch and flow injection sampling formats is presented. Detection via atomic absorption spectrometry (AAS), microwave induced plasma optical emission spectrometry (MIP-OES), inductively coupled plasma optical emission spectrometry (ICP-OES) , inductively coupled plasma mass spectrometry (ICP-MS) and furnace atomic nonthermal excitation spectrometry (FANES) are considered. Hydride generation is separately considered in contrast to other methods of generation of volatile derivatives. Hg <FONT FACE=Symbol>¾</FONT> CVAAS (cold vapor atomic absorption spectrometry) is not considered here. The current state-of-the-art, including extension, advantages and limitations of this approach is discussed.