Philippine Journal of Science
150 (5): 1093-1108, October 2021
ISSN 0031 – 7683
Date Received: 21 Jan 2021

Development, Validation, and Application
of a Three-way Cleanup Method for GC/MS Measurement
of PCBs in Stranded Cetaceans in Philippine Waters

Jonah L. Bondoc^1,2*, Lemnuel V. Aragones², and Charita S. Kwan^1,2

¹Research and Analytical Services Laboratory (RASL)
Natural Sciences Research Institute (NSRI)
University of the Philippines, Diliman 1101 Quezon City, Philippines
²Institute of Environmental Science and Meteorology
University of the Philippines, Diliman 1101 Quezon City, Philippines

*Corresponding author: jlbondoc@up.edu.ph

 

ABSTRACT

 

Polychlorinated biphenyls (PCBs) are a group of synthetic organic chemicals that enrich the food chain via biomagnification where the highest levels have been detected in cetaceans. While several studies have reported cetaceans as sentinels of environmental pollution, information on the contamination status of PCBs in cetaceans found stranded along Philippine coasts has been very limited over the past decades. An important contributory factor to this paucity is the challenging analytical method for the analysis of PCBs in lipid-rich biological tissues due to lipid interferences that can affect gas chromatographic systems especially column efficiency and lifetime. Thus, a modified method consisting of a series of three cleanup steps – involving isolation column chromatography, gel permeation chromatography (GPC), and solid-phase extraction (SPE) using silica gel following Soxhlet extraction, plus macro- and micro-concentration prior to gas chromatographic/mass spectrometric analyses – was used. Recovery of added analytes corresponding to appropriate concentration ranges and repeatability of data values were excellent as values obtained were within the established performance criteria of 40–120% recovery, including a 106% mean recovery for the QC material (FAPAS T05100QC – Oily Fish) and < 30% RSD for an analyte concentration of 1 µg kg–1. Thus, the modified cleanup technique in conjunction with GC/MS detection is proven suitable for its intended use. Thirtyeight (38) congeners (PCBs-8, -12, -19, -18, -33, -38, -35, -37, -52, -44, -57, -74, -79, -78, -81, -77, -104, -99, -123, -118, -114, -126, -155, -153, -162, -167, -156, -157, -169, -188, -189, -202, -195, -194, -205, -208, -206, and -209) were detected in cetacean blubber (n = 15) ranging from 21.7 ng g–1 lipid weight (in an adult female dwarf sperm whale (Kogia sima) found in Camarines Sur) to 1460 ng g–1 lipid weight (in an adult male rough-toothed dolphin (Steno bredanensis) found in Zambales.