Overview
ISO 18856:2004 specifies an analytical method for the determination of selected phthalates in water by solid phase extraction (SPE) followed by gas chromatography/mass spectrometry (GC/MS). It applies to phthalates in groundwater, surface water, wastewater and drinking water at mass concentrations from just above 0.02 µg/L up to 0.150 µg/L, depending on the substance and blank values. The standard lists 11 target phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DCHP, DEHP, DOP, DDcP, DUP) and allows extension to other phthalates after verification of applicability.
Key topics and requirements
- Analytical principle: enrichment by SPE (reversed-phase C18 or equivalent) → separation on capillary GC columns → identification and quantification by MS.
- Target analytes: the standard defines specific phthalates (Table 1) with CAS numbers and abbreviations; applicability to other phthalates must be validated case-by-case.
- Quantitation range: method applicability from ~0.02 µg/L to 0.150 µg/L (substance-dependent).
- Contamination control: strict measures to avoid ubiquitous phthalate contamination - use glass equipment, avoid plastics, control laboratory air, use appropriate septa and cleaned apparatus. Maximum allowed blank level cited (see standard and Annex C).
- Reagents & standards: use high-purity solvents (e.g., ethyl acetate, methanol, isooctane), high-purity gases (He, N2), aluminium oxide or alternative sorbents, and internal standards (examples: D4-DBP, D4-DOP, diallyl phthalate).
- Apparatus: SPE cartridges, glass reservoirs, GC capillary columns and GC/MS instrumentation; examples and recommendations for columns, conditions and equipment to avoid contamination are provided in informative annexes.
- Quality control: calibration (multipoint), recovery checks, blank determinations, precision data and reporting requirements are included.
Applications and users
- Environmental and water quality laboratories performing phthalate monitoring in drinking water, surface water, groundwater and treated/untreated wastewater.
- Regulatory agencies and utilities requiring a standardized GC/MS method for compliance testing and inter-laboratory comparison.
- Contract analytical labs and researchers studying plasticizer contamination, fate and transport of phthalates, or evaluating remediation/treatment performance.
Related standards
- ISO 5667 series (sampling guidance): ISO 5667-1, ISO 5667-2, ISO 5667-3 - referenced for sampling design, techniques and sample preservation.
- Annexes in ISO 18856 provide practical guidance (lists of phthalates, recovery/internal standard remarks, equipment avoidance, GC conditions, precision data).
Keywords: ISO 18856:2004, phthalates, water quality, GC/MS, solid phase extraction, SPE, drinking water testing, environmental monitoring, analytical method, contamination control.
Open preview (PDF)Water quality — Determination of selected phthalates using gas chromatography/mass spectrometry