She flipped the worksheet over. On the back was the final section she’d added for her most advanced students: The last question read: If your result contradicts the official record, do you trust your instrument or the authority? Justify your answer based on the principles of atomic absorption.
She aspirated the new solution. The hollow cathode lamp for lead flickered to life, shooting a precise violet beam through the flame. The detector chattered. The software plotted a new point. atomic absorption spectroscopy worksheet
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. She flipped the worksheet over
She glanced at the second section: Digest the sample using a 1:1 nitric acid solution. Filter. Dilute to volume. She had done this. She had taken water from the riverbank, just below the old battery plant. But when she ran the sample through the AAS—that beautiful, humming machine that shattered light into element-specific wavelengths—the result matched the EPA’s lie: 0.48 ppm. Safe. She aspirated the new solution
Section 3 was where things got interesting: List three spectral interferences and two chemical interferences that could cause false low results.
Too safe.
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.