Arsenic (As) standard solution at 10,000 µg/mL in 2.0 mol/L nitric acid (HNO3). Primarily used as a calibration standard for trace-level arsenic determination in analytical chemistry via techniques such as atomic absorption spectroscopy (AAS), inductively coupled plasma optical emission spectrometry (ICP-OES), or ICP-mass spectrometry (ICP-MS). Essential for environmental monitoring (e.g., water and soil), food and beverage safety testing, pharmaceutical quality control, and industrial hygiene assessments to detect arsenic contamination. In semiconductor manufacturing, high-purity arsenic sources derived from such solutions may support doping processes for n-type semiconductors. Due to arsenic's extreme toxicity and potential carcinogenicity, strict safety protocols, including fume hood use, PPE, and proper waste disposal, are required.