REMOVAL OF POLYCHLORINATED BIPHENYLS (PCBs) FROM WATER DOWN TO PARTS PER TRILLION
CASE STUDY N°.: 5
PetroBarrier Systems and Camosun College
Experiments were carried out to establish the percent removal of polychlorinated biphenyls (PCBs) from a low concentration water solution (5 ppb of PCB 28 and PCB 52). Filtration experiments and chemical analysis was carried at Camosun College in the analytical chemistry lab. Filter materials were prepared in advance by Petrol barrier systems. Chemical analysis of (PCBs) was achieved using a gas chromatograph/mass spectrometer (GC/MS) following good lab practices (GLP) and standard quality assurance (QA) procedures. All lab procedures employed are based on published methods1,2. Quantitation of each will be based on calibration using standard solutions at known relevant concentrations using reference compounds and when possible an internal standard(s).
Description of Work
Two filter materials were investigated. A carbon/honey comb column and a carbon/PVC column. Each material was treated separately as described below.
Each column was wetted by passing 1 L of deionized water through. The water was collected in a beaker and analyzed by GC/MS. This served as the procedure blank. A 1 L sample of deionized water was fortified as described below to make a 5ppb PCB aqueous solution. This solution was mixed thoroughly and a 4 mL portion was taken for GC/MS analysis. Next the 5 ppb solution was passed through the filter and collected into a 1000 mL beaker. The full volume of 1 L was allowed to completely pass through the filter. This solution was mixed thoroughly and a portion was taken for GC/MS analysis.
Figure 1. Picture of the filtration column and beakers used for sample collection
Too allow for solid phase microextraction or SPME a 4 ml of each solution was pipetted into a 10 ml headspace vial. Then internal standard solution (containing pyrene-d10) was pipetted in to each vial. Next 1.5 g of NaCl was added to each solution.
Calibration, QA/QC, and Results
The following steps were taken to ensure the overall quality of results.
A four point calibration curve was prepared for each PCB and is provided below.
Figure 2. PCB Calibration Curves (concentration range 3ng/L to 500 ng/L)
- Two procedure blanks were prepared as described above and no PCB’s were detected.
- After filtration a duplicate of each sample was taken for analysis.
The concentration of PCB’s in the one liter water sample was prepared at a nominal value of 5000 ng/L (parts per trillion). The measured concentration and the average % removal of each PCB after filtering is shown in the table below. Note that duplicate measurements were made for each PCB.
Table 1. Results from Filtration Experiment
*A standard PDMS/PVB fiber was used for extraction
- EPA Method 8272. http://www.epa.gov/solidwaste/hazard/testmethods/pdfs/8272.pdf
- J Chromatogr A. 1998 Mar 27;800(2):257-66. Solid-phase microextraction of polychlorinated biphenyls.
Prepared by: Blair Surridge (Instructor and Analytical Chemist Researcher)_____Blair Surridge___