Griess Assay of Salivary Nitrite Content with Extraction Preconcentration

Abstract

Nitrite has been determined using a simple and sensitive spectrophotometric method. The suggested procedure is based on the diazotization reaction of p-bromoaniline in the presence of nitrite ion in a hydrochloric acid media, which produces diazonium salt. This salt is then combined with paracetamol in an ammonium hydroxide medium to produce an orange azo color with a maximum wavelength (λ max.) of 460 nm, molar absorptivity (ε) is 3.8432 x 103 L. mol-l.cm-1, and Beer’s law was established between 0.3-12.0 µg. mL-1. It displays LOD, LOQ, and R2 values of 0.2 µg. mL-1, 0.3 µg. mL-1, and 0.9994 respectively. The dye can be extracted into chloroform. The yellow chloroform extract displays a maximum wavelength (λ max.) of 410 nm, molar absorptivity (ε) is 9.93 x103 L. mol-l.cm-1, and Beer’s law was observed between 0.1-5.0 µg. mL-1. The LOD, LOQ, and R2 values for the suggested extraction procedure were 0.05 µg. mL-1, 0.1 µg. mL-1, and 0.9996, respectively. The suggested method was successfully applied on samples of a human saliva.

Keywords

• nitrite
• griess assay
• spectrophotometry
• liquid-liquid extraction
• paracetamol