12. Calibration and Standardization
12.1 Using the chloride standard stock solution (see 8.21),
make a series of three calibration standards covering the range
of expected chloride concentration.
12.2 Into three 100-mL volumetric flasks, respectively pipet
1, 15, and 30 mL of chloride stock solution and dilute to the
mark with solvent. (The standards are approximately 1 mg
Cl/mL, 15 mg Cl/mL H and 30 mg Cl/mL.)
12.3 It is customary to use a one-point calibration, but if
analyzing a wide range of samples, use a three-point calibration.
12.4 The sample size can be determined either volumetrically, by syringe, or by mass. Make sure that the sample size is
80 % or less of the syringe capacity.
12.4.1 Volumetric measurement can be utilized by filling the
syringe with standard, carefully eliminating all bubbles, and
pushing the plunger to a calibrated mark on the syringe, and
recording the volume of liquid in the syringe. After injecting
the standard, read the volume remaining in the syringe. The
difference between the two volume readings is the volume of
standard injected. This test method requires the known or
measured density, to the third decimal place. Several densities
of various hydrocarbons are listed in Table 1.