TABLE IV

Composition of Extracts of the Polypropylene Resin

pH		Concentration of Analytes (mg/L)
Prepared	Measured	Ca	Zn	Stearate	Palmitate	Net TOC (1)
Low pH, 0.05 M sodium phosphate buffer
2.5	2.6	0.16	0.04	<0.01	0.01	0.6
3.0	3.1	0.10	0.02	<0.01	0.01	0.7
3.5	3.6	0.09	0.02	<0.01	0.01	0.8
4.0	4.1	0.16	0.04	<0.01	0.01	0.8
4.5	4.7	0.08	0.02	<0.01	0.01	0.8
Intermediate pH, 0.05 M potassium phosphate buffer
5.0	5.1	0.04	0.02	0.04	0.04	<0.1
5.5	5.6	0.05	0.02	0.03	0.04	2.2
6.0	6.1	0.05	0.02	0.03	0.04	0.4
6.5	6.6	0.06	0.02	0.03	0.04	<0.1
7.0	7.0	0.06	0.01	0.03	0.05	0.3
7.5	7.5	0.08	0.02	0.04	0.06	1.3
High pH, 0.025 M borax (sodium tertaborate decihydrate) buffer
8.0	8.1	0.09	<0.01	0.05	0.35	1.1
8.5	8.7	0.04	0.01	0.35	1.98	1.7
9.0	9.1	0.04	0.01	1.39	2.46	1.0
9.5	9.5	0.02	0.02	2.66	5.61	1.4
10.0	10.0	0.01	<0.01	4.30	8.37	3.5
10.5	10.3	0.02	<0.01	6.05	8.34	3.0
11.0	10.4	0.01	<0.01	7.07	7.75	3.1

Note: (1) TOC = Total organic carbon. Extracted TOC = TOC in extract − TOC in extraction blank.