Verification method on determination of chemical oxygen demand for hospital wastewater

• Published in: AIP conference proceedings 2022-12, Vol.2645 (1)
• Main Authors: Rohyami, Yuli, Berliana, Carina Devi, Wati, Dewi Agustina
• Format: Article
• Language: English
• Subjects: Acceptability; Calibration; Chemical oxygen demand; Confidence intervals; Correlation coefficients; Linearity; Quality control; Spectrophotometry; Verification; Wastewater
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0112736

Verification method on determination of chemical oxygen demand (COD) in hospital wastewater with close reflux by UV-Vis spectrophotometry have been carried out. Verification method is used to determine the acceptability requirements in quality control at the Indonesian Nasional Standard (SNI 06-6989.2:2019). The testing parameters of verification method include linearity, limit of linearity (LOL), limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy. Based on the calibration curve if the COD standard series has linearity in accordance with the standard with correlation coefficient (r) of 0.9975 and determination coefficient (R) of 0.9975. Determination of the limit of linearity (LoL) with degree of freedom, df1 =df2 = 9 and internal confidence level of 95% obtained F test = 0.3490 ≤ F table = 6.057 indicates that the calibration curve satisfies the linearity and is accepted as the calibration curve. The limit of detection (LOD) is 7.5779 mg/L, therefore the minimum COD value can be detected with significant response. The limit of quantification is 25.2596 mg/L which shows that the minimum COD value can be determined. This method has high precision with acceptability requirements with % RSD is 3.2205% and CV Horwitz is 4.1356%. The trueness percentage is 103.49% in accordance with acceptability quality requirements with the range 85 – 110 % indicating that this methods has high accuracy.