A microfluidic paper-based analytical device for rapid quantification of particulate chromium

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Occupational exposure to chromium (Cr) poses significant health risks.
• Current methods for assessing chromium exposure, such as inductively coupled plasma-mass spectrometry (ICP-MS), are costly and resource-intensive.
• There is a need for accessible and affordable methods to monitor chromium levels in the environment.

Purpose of the Study:

• To develop a novel, simple, and inexpensive microfluidic paper-based analytical device (μPAD) for measuring total chromium in airborne particulate matter.
• To demonstrate the feasibility of using μPAD for occupational and environmental monitoring of chromium.

Main Methods:

• A microfluidic paper-based analytical device (μPAD) was designed for chromium analysis.
• Tetravalent cerium (Ce(IV)) was employed in a pretreatment zone to oxidize soluble chromium to Cr(VI).
• Cr(VI) was detected in the detection zone using 1,5-diphenylcarbazide (1,5-DPC), forming a colored complex with Cr(III) for quantification.

Main Results:

• The μPAD demonstrated a log-linear working range between chromium concentration and color intensity (0.23-3.75 μg; r(2)=0.998).
• A low detection limit of 0.12 μg for total chromium was achieved.
• Validation using a certified reference material containing competing metals showed quantitative agreement with known chromium levels.

Conclusions:

• The developed μPAD is a viable, cost-effective tool for quantifying total chromium in airborne particulate matter.
• This technology offers a promising alternative to sophisticated instrumental techniques for chromium exposure assessment.
• The μPAD facilitates accessible environmental and occupational health monitoring.