But tonight, the curve wasn't for a classroom. It was for the cold case of the Meridian River. For six months, the EPA had claimed the lead levels were safe. Elara suspected a lie. The townspeople were sick. The fish were dying. But the official reports showed a clean, linear slope—a perfect correlation.
Elara didn't write an answer. She printed the new data, stapled the old worksheet to it, and walked to the district attorney’s office.
The worksheet wasn’t just a training tool anymore. It was a roadmap. It had taught her to question the blank, to seek the signal beneath the noise, and to never trust a clear solution without checking for interference. atomic absorption spectroscopy worksheet
Dr. Elara Vance stared at the worksheet on her lab bench. It wasn't just any worksheet; it was the worksheet—the one she’d designed a decade ago as a teaching assistant, now smudged with coffee rings and the graphite ghosts of erased answers.
Not safe. Deadly.
“Section 1: Calibration Curve,” she read aloud, her breath fogging her safety glasses. On the worksheet, it was a simple instruction: Plot absorbance vs. concentration for lead standards (0.5, 1.0, 2.0 ppm).
Section 3 was where things got interesting: List three spectral interferences and two chemical interferences that could cause false low results. But tonight, the curve wasn't for a classroom
The Trace Evidence