Rapid assessment of soil accessible Cr(â
¥) in the field by a portable RGB color sensor.
Ecotoxicol Environ Saf
; 273: 116117, 2024 Mar 15.
Article
in En
| MEDLINE
| ID: mdl-38377780
ABSTRACT
Field rapid determination of soil accessible Cr(â
¥) is of great significance for on-site assessment and decision-making about the health risks of contaminated sites. When the thickness of solutions with various concentrations of Cr(â
¥) is constant, there would be a quantitative relationship between the chromogenic difference of Cr(â
¥) solutions and the concentration of Cr(â
¥). The chromogenic difference could be described by Red (R), Green (G), Blue (B) values. Based on the chromogenic reaction between 1,5-diphenylcarbazide and Cr(â
¥), this study first established the calibration curve between the chromogenic difference and the concentration of Cr(â
¥) in standard solution with or without 0.01â¯M CaCl2, using an RGB color sensor. This is the subsequent determination basis of the method for rapidly assessing accessible Cr(â
¥) in the field (M-RGB). Then, the concentration of accessible Cr(â
¥) of contaminated soil with "hand-shaking + standing" field extraction method was compared with "end-over-end shaking" laboratory extraction method. Finally, the accessible Cr(â
¥) of contaminated soil extractants was determined via M-RGB integrating the field extraction method. Results indicated there was a highly significant linear relationship between colorimetric difference value (∆E) and Cr(â
¥) concentration in the range of 0.1-3â¯mg/L (R2 > 0.99, P < 0.01), based on the Euclidean formula for calculating ∆E. The "hand-shaking + standing" field extraction method was effective in obtaining accessible Cr(â
¥) extractants with or without 0.01â¯M CaCl2, with the high extraction efficiency within 100±1%. The concentrations of accessible Cr(â
¥) in various polluted soils determined by M-RGB were consistent with that determined by the ultraviolet-visible spectrophotometry, with the relative error within ±5%, and the relative standard deviation ≤ 20%. The spiked recovery experiments showed that the recovery of M-RGB was between 95% and 105%, which means M-RGB could realize the trace analysis for accessible Cr(â
¥) in the field.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Soil
/
Chromium
Language:
En
Journal:
Ecotoxicol Environ Saf
Year:
2024
Document type:
Article
Affiliation country:
China
Country of publication:
Netherlands