研究目的
To develop a method and device for rapid measurement of nitrate levels in aqueous solutions based on spectrophotometric method.
研究成果
The developed method and device enable rapid, reagent-free measurement of nitrate concentrations in water with an error not exceeding 10% for levels above 10 mg/L, using UV-LEDs and spectrophotometry. It offers advantages in speed, cost, and real-time monitoring compared to existing methods, with potential applications in water quality control and various industries. Future work should focus on enhancing accuracy for low concentrations and enabling wireless data transmission.
研究不足
The device has a measurement error of up to 10% for concentrations above 10 mg/L; accuracy may be affected by other impurities like fulvic acids in water; the method is optimized for transparent aqueous solutions and may require improvements for highly colored waters; the current prototype is connected to a PC and not fully portable.
1：Experimental Design and Method Selection:
The method involves spectrophotometry using UV-LEDs to irradiate water samples and measure optical density at three wavelengths (285 nm, 310 nm, 346 nm) to determine nitrate concentration. A mathematical model based on the area under the optical density curve is used for calculation.
2：Sample Selection and Data Sources:
Aqueous solutions with varying nitrate concentrations (e.g., 8 mg/L to 300 mg/L) were prepared using tap water and KNO3 solutions. Distilled water was also used for baseline measurements.
3：List of Experimental Equipment and Materials:
UV-LEDs (emitting in 285-365 nm range), photodiode with light sensitivity of 10^-5 A/W, 10-bit ADC for data processing, cuvettes for holding samples, personal computer for data collection and analysis.
4：Experimental Procedures and Operational Workflow:
Samples are irradiated with UV light at specified wavelengths; optical density is measured using a photodiode; data is digitized by ADC and processed by software to calculate nitrate concentration based on the area method; measurements are taken in real-time with a duration of less than 1 second per sample.
5：Data Analysis Methods:
Data is analyzed using a mathematical algorithm that calculates the area under the optical density vs. wavelength curve for three points, with calibration against known concentrations to reduce errors.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
