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The Physikalisch-Technische Bundesanstalt (PTB) is the national metrology institute of the Federal Republic of Germany and has been using synchrotron radiation (SR) for more than 40 years. Starting at the former facility BESSY I, the storage ring BESSY II (see corresponding article in this volume) has been used for this purpose since 1998, especially in the X-ray range, as well as PTB's own metrology light source (MLS) for lower photon energies since 2008. Both facilities are located in Berlin-Adlershof and are operated by the Helmholtz-Zentrum Berlin within the framework of contractual agreements with PTB. The basic motivation of the work is radiometry. The two storage rings MLS and BESSY II are used as primary source standards and cryogenic radiometers as primary detector standards. The article gives a brief overview of the present status, scientific highlights, the technological development and upgrade plans for the decade 2023–2033 as well as a perspective of next scientific challenges.

Alcoholic beverages contaminated with scopolamine (SCP) are often employed for criminal purposes due to their sedative effect. The determination of the residual levels of SCP in body fluids (e.g., urine) can help to track possible victims of induced ingestions. Biological sample analysis usually requires a preconcentration step to enhance their detectability and to provide sample clean-up. Molecularly imprinted polymers (MIPs) in lieu of conventional solid sorbents represent an enhancement of selectivity, due to their specific recognition sites. Additionally, the adaptation of the solid-phase extraction (SPE) cartridge into a disposable pipette tip extraction (DPX) contributes to the miniaturization of the sample preparation step. Herein, an analytical method for the determination of SCP in synthetic urine samples via the integration of molecularly imprinted solid-phase extraction (MISPE) with DPX as a preconcentration step prior to capillary electrophoresis analysis (also known as MISPE-DPX-CE) is presented. The extraction and elution steps were optimized using a factorial design. Using the optimized conditions, a preconcentration factor of 20 was obtained, leading to a working range of 0.5–6 µM with LOD of 0.04 µM and repeatability of 6.4% (n = 7) and adequate recovery values (84 and 101%) The proposed MISPE-DPX-CE approach was successfully applied to selective extraction, preconcentration, and determination of SCP in synthetic urine samples.

Este trabalho fundamentou-se no estudo de processos EC\' que ocorrem nos sistemas ferrocenometanol/ascorbato e iodeto/tiossulfato e no aproveitamento do mecanismo EC\' para incrementar a corrente oriunda de processos de oxidação anódica envolvendo ascorbato e iodeto. Inicialmente, foram realizadas investigações com macroeletrodos e em etapa subsequente foram empregados microeletrodos. Com o intuito de otimizar os parâmetros experimentais, estudou-se a influência da concentração das substâncias, pH das soluções e velocidade de varredura. Experimentos posteriores foram feitos utilizando a técnica de Microscopia Eletroquímica de Varredura (SECM) com o objetivo de confinar as espécies envolvidas e obter um incremento de sinal pelo efeito de retroalimentação (redox cycling). Amostras de suco de fruta e urina sintética foram analisadas para validar os métodos propostos. Concluiu-se que a determinação de iodeto e ascorbato pode se tornar mais sensível aproveitando-se o fenômeno de regeneração via mecanismo EC\' e o confinamento dos reagentes e produtos estabelecido quando um microeletrodo se encontra próximo a um substrato (configuração SECM). This work was based on the study of EC\' processes that occur in the ferrocenemethanol/ascorbate and iodide/thiosulfate systems and the use of the EC\' mechanism to increase the current from anodic oxidation processes involving ascorbate and iodide. Initially, investigations were carried out with macroelectrodes, and, in a subsequent step, microelectrodes were used. The influence of concentration, solution pH, and scan rate was studied to optimize the experimental conditions. Further experiments were carried out using Scanning Electrochemical Microscopy (SECM) as an attempt to confine the species involved in the system and to obtain a current increment because of the redox cycling effect. Juice fruit and synthetic urine samples were analyzed to evaluate the usefulness of the proposed approach. The determination of iodide and ascorbate can become more sensitive by taking advantage of the regeneration via the EC mechanism and the confinement of reagents and products established when a microelectrode is located close to a substrate (SECM configuration).