Multivariate analysis of identity of imported technical PCN formulation

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Chloronaphthalenes (CNs) are a class of 75 congeners grouped into 8 homologue groups, extensively used from 1930-1950.
• Recent illegal importation of an unidentified technical CN formulation from the UK to Japan necessitated an origin investigation.

Purpose of the Study:

• To identify the origin of an unlawfully imported technical chloronaphthalene (CN) formulation.
• To compare the composition of the imported CN with known technical formulations, specifically Halowax.

Main Methods:

• High-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) was used to obtain isomer-specific and homologue class compositional data for CNs.
• Multivariate statistical analyses, including Principal Component Analysis (PCA) and Cluster Analysis, were applied to the compositional data.

Main Results:

• The imported CN formulation was definitively identified as not being Halowax 1001.
• While homologue class patterns suggested similarity to Halowax 1001, congener-specific analysis revealed distinct origins.
• The chlorine content (50-52%) and compositional data did not match Halowax 1001.

Conclusions:

• The unlawfully imported chloronaphthalene mixture is unlikely to be Halowax 1001.
• Based on chemical profile and chlorine content, the mixture is likely a sample of stockpiled Seekay wax R93.