ASTM D3348 Rapid Field Test for Trace Lead in Unleaded Gasoline
ASTM D3348 Standard Test Method for Rapid Field Test for Trace Lead in Unleaded Gasoline (Colorimetric Method)
9. Procedure
9.1 Prepare the sample in accordance with the directions given in 8.1.1-8.1.5.
NOTE 9 - Short form instructions are outlined in Appendix X1.
9.2 Place the test tube containing the water in the colorimeter and set the absorbance to zero, or to 100 % transmittance.
9.3 Place the sample in the colorimeter and read the absorbance or percent transmittance.
NOTE 10 - Time Limit - The PAR-lead solution obtained for the sample in 9.1 must be read within 10 min after the step described in 8.1.5.
9.4 From the calibration curve, find the lead content of the sample. Determine the lead content to the nearest 0.001 g/gal (0.26 mg/L) value. Report the lead content to 0.01 g/gal (2.64 mg/L).
NOTE 11 - The lead content may be obtained from the calibration curve to three significant figures (0.001 g/gal); however, the value must be rounded to two significant figures (0.01 g/gal) for reporting purposes. When the third digit is 5 the value should be rounded to the nearest even number. For example, 0.035 g/gal would be reported as 0.04 g/gal, while 0.045 g/gal would also be reported as 0.04 g/gal.
