Fig. 2From: Evaluation of an online, real-time, soft-photon ionisation time-of-flight mass spectrometer for mainstream tobacco smoke analysisControl chart for toluene as (μg/puff), showing overall variability in repeat measurements. Data were recorded over 5 days with 3, 6, 4, 5 and 12 repeat measurements per run. Top, individual measurements (n = 30). Bottom, moving rangeBack to article page