External standard mode of instrument calibration

To illustrate the external standard mode of instrument calibration and subsequent quantitative analysis, a real analysis of the author s drinking water is sampled at the kitchen faucet and at the refrigerator faucet. Both sampling sites are derived from the same source, municipal drinking water from Meridian Township, Michigan. Both samples were reported to contain all four trihalomethanes. This author was surprised to observe that with the exception of chloroform, the other three THMs were somewhat lower in concentration in tepid water versus refrigerator chilled water To this... 

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