Construction of a long-pathlength flow cell for spectrophotometric measurements

Química Nova

Raimundo Jr., Ivo M.¹  Universidade de São Paulo, São Paulo, Brasil¹  Rocha, Fábio R. P.¹  Universidade Estadual de Campinas, Campinas, Brasil¹  Melchert, Wanessa Roberto¹  Reis, Boaventura F.¹  Universidade de São Paulo, Piracicaba, Brasil¹ 

关键词: long pathlength spectrophotometry;    flow analysis;    liquid core waveguide.;   

DOI  :  10.1590/S0100-40422008000200042

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

A simple and low-cost flow cell with 30 cm optical path for spectrophotometric measurements is described. It presents desirable characteristics such as low attenuation of the radiation beam and internal volume (75 µL) comparable to that of a 1-cm conventional cell (80 µL). Despite the increase in optical path, the effect on sample dispersion was also similar to that attained in the commercial cell. The performance of the cell was assessed by the determination of phosphate based on the molybdenum blue method, yielding a linear response range between 0.05 and 0.8 mg L-1 phosphorus (r=0.999). The increase in sensitivity (30.4-fold) in comparison with that obtained with a conventional 1-cm flow cell agreed with that estimated by the Lambert-Beer law.

【 授权许可】

Unknown