|
| Determination of nitrite content in human urine by spectrophotometry with solid-phase extraction |
| Received:September 17, 2023 Revised:January 19, 2024 |
| View Full Text View/Add Comment Download reader |
| DOI： |
| KeyWord:spectrophotometry; solid phase extraction; nitrite; urine |
| Author | Institution |
| WANG Ruiping |
广州市第十二人民医院 |
| CHEN Jiu |
广州市第十二人民医院 |
| Wang Zhi |
广州市第十二人民医院 |
|
| Hits: 222 |
| Download times: 158 |
| Abstract: |
| In order to achieve rapid and accurate determination of nitrite content in human urine when nitrite poisoning occurs, a method of solid-phase extraction (SPE) coupled with spectrophotometry was established. The method was based on the diazo-coupling reaction of nitrite , and purified urine using SPE technique to eliminate the interference of matrix and improve the testing sensitivity. The influence of different operating parameters such as type of SPE columns, type of diazotization agents, concentration of diazotization agent, reaction acidity, concentration of coupling agent, reaction time were compared and studied, and the optimum experimental conditions were obtained, and the testing method was determined. The urine sample was centrifuged, and the supernatant was purified with the HLB SPE column. The extract urine 2.0 mL was transferred to a colorimetric tube, and diluted to the volume of 5.0 mL with water, and 0.5 mL of the sulfanilamide acid solution(50.0 g/L) and 0.5 mL of N-(1-Naphthyl)ethylenediamine dihydrochloride solution(2.5 g/L) were added in, the mixture was mingled completely and settled for 10 min for diazo-coupling color reaction, and then measured at 544 nm by spectrophotometry and quantified by working curve in external standard method. The results showed that nitrite had a good linear relationship in the range of 0.033-0.986 μg/mL and the correlation coefficient was 0.9998. The spiked recoveries of nitrite in urine samples were ranged from 96.3% to 106.1% at three spiked levels from 0.246-2.054 μg/mL, indicating that the interfering substances that affect the diazo-coupling reaction were successfully removed by the HLB SPE column, and the purification effect was satisfied. The relative standard deviations (RSD) for intra-day and inter-day were ranged from 2.01% to 3.58% and from 2.21% to 4.75%, respectively, and the limit of detection was 0.010 μg/mL and the limit of quantification was 0.033 μg/mL. The method has the advantages of simple operation, fast detection speed, good precision, high accuracy and low detection limit, it can be used for the rapid determination of nitrite in human urine. |
| Close |
|
|
|