A digital image method of spot tests for determination of copper in sugar cane spirits

作者：Pessoa Kenia Dias; Suarez Willian Toito; dos Reis Marina Ferreira; Krambeck Franco Mathews de Oliveira; Lopes Moreira Renata Pereira; dos Santos Vagner Bezerra

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2017, 185: 310-316.

DOI：10.1016/j.saa.2017.05.072

• Digital image analysis
• RGB model
• Sugar cane spirits
• Copper
• Spot test

In this work the development and validation of analytical methodology for determination of copper in sugarcane spirit samples is carried out. The digital image based (DIB) method was applied along with spot test from the colorimetric reaction employing the RGB color model. For the determination of copper concentration, it was used the cuprizone - a bidentate organic reagent - which forms with copper a blue chelate in an alkaline medium. A linear calibration curve over the concentration range from 0.75 to 5.00 mg L-1 (r(2) = 0.9988) was obtained and limits of detection and quantification of 0.078 mg L-1 and 0.26 mg L-1 were acquired, respectively. For the accuracy studies, recovery percentages ranged from 98 to 104% were obtained. The comparison of cooper concentration results in sugar cane spirits using the DIB method and Flame Atomic Absorption Spectrometry as reference method showed no significant differences between both methods, which were performed using the paired t-test in 95% of confidence level. Thus, the spot test method associated with DIB allows the use of devices as digital cameras and smartphones to evaluate colorimetric reaction with low waste generation, practicality, quickness, accuracy, precision, high portability and low-cost.

• 出版日期2017-10-5