Determinação voltamétrica de zinco empregando eletrodos quimicamente modificados com bismuto

This dissertation presents the development of voltammetric methods to zinc determination in multivitamin commercial samples, talc, and art materials for painting (soft pastel) combining an alkaline extraction with 1.0 mol L-1 NaOH aqueous solution and bismuth modified electrodes. Two electrodes were used to zinc quantification in the samples, bismuth film electrode (BiFE) plated in situ onto glassy carbon and carbon paste electrode chemically modified with strongly acidic ion exchange resin Amberlite® IR 120 and bismuth nanostructures (EPCAmbBi). It was verified that the best concentration of Bi3+ for Bi film deposition onto glassy carbon was 4.0 μmol L-1 using an 0.1 mol L-1 acetate buffer aqueous solution (pH = 4.5) as supporting electrolyte. The best condition to formation of Bi nanostructures in the EPC modified with 10 % Amberlite® IR 120 was the use of 30 s to pre-concentration (open circuit) in 0.5 mmol L-1 Bi3+ aqueous solution (pH 5.5) prepared with supporting electrolyte solution. The obtained analytical curve for Zn2+ using BiFE presented linear range from 0.5 to 5.0 μmol L-1, the limit of detection (LD) was 41 nmol L-1. For EPCAmbBi only one linear range was observed for the analytical curve varying the Zn2+ concentration from 0.05 to 8.2 μmol L-1, LD obtained in this curve it was equal to 10 nmol L-1. The EPCAmbBi presented the most intense and sharp anodic stripping peaks for Zn2+ presenting, therefore, a better voltammetric profile, with sensitivity higher than obtained with the BiFE. Moreover, the EPCAmbBi presented a LD lower than that obtained with the BiFE. Alkaline extraction was an efficient sample pretreatment to extract Zn2+ from solid samples, besides that, this procedure was less susceptible to interferences from Cu2+, since it remains at extracting vessel as insoluble Cu(OH)2. The combination of alkaline extraction with the EPCAmbBi is a simple, fast, efficient and low cost for the zinc determination in pharmaceutical formulations and art materials for painting (soft pastel) samples, which can be employed as a low-cost alternative method to the atomic absorption spectroscopy.

Internação involuntária e o abuso de substâncias psicoativas - o pathos familiar

The use and abuse of Psychoactive Substances (PAS) in contemporaneity corresponds to a social issue and a public health issue. Few social phenomena entail more costs with justice and health, family difficulties, and appearances in the media than the PAS abuse comsumption. The government power has been facing this situation allocating investments and developing public policies. Despite the current Mental Health Policy, based on the principles of Psychiatric Reform that prioritizes outpatient services, the number of investments from various government spheres and families requests for admissions continue increasing. This study aimed to understand the pathos experienced by an individual toward the involuntary internment of a family member who is an abusive user of PAS. The research also aimed to investigate what led that individual to choose this type of treatment. The Psychoanalysis was the theoretical basis of this work, and the exercise of the psychoanalytic method, from the collection of bibliographic references up to the interpretation of the semi-structured interview, conducted in depth, was intended. The findings of this research gave us the oportunity of thinking about how the social callings to the family were made, especially in regard of atention and care with their family members who are user of PAS and how it affects this family individual. It also allowed to discuss how the public policies that preconize involuntary internment, affectivity, prohibitionist and mono-disciplinarity – that cross the State in the attention given to this issue – are formulated and implemented. The interview analysis showed us how happen the agencying of pathos, the libidinal aspects of joy and guilt, the desire to punish and atonement, working in family relations and in caring relations, especially in the decision for involuntary internment. The survey also made possible to understand how a mother, facing the chaotic scene of public health, helpless, finds in the involuntary internment a way to reverberate her affections.