National Measurement Institute

Solid samples

We recommend the following preservation procedures, holding times and conditions when submitting solid samples for National Measurement Institute (NMI) testing. Please treat these recommendations as a guide only.
Test Container Sample size Preservation procedure (treatment after collection until arrival at NMI) Holding time (maximum time from collection until analysis) Reference
Bromide plastic or glass 20 g air dry or field moist 28 days NEPM
Carbon (TOC) glass 20 g air dry or field moist 28 days NEPM
Chloride plastic or glass 20 g air dry or field moist 28 days NEPM
Conductivity plastic or glass 20 g air dry or field moist 7 days NEPM
Cyanides plastic or glass 20 g field moist 14 days NEPM
Dioxins glass 100 g cool to <4 °C 1 year until (1 after) extraction US EPA 1613
Fluoride plastic or glass 20 g air dry or field moist 28 days NEPM
Herbicides glass 20 g or 1 x 125 mL cool to <4 °C 14 days US EPA SW-846
Hexavalent chromium plastic 20 g field moist 28 days NEPM
Mercury plastic 20 g field moist 28 days NEPM
Metals plastic or glass 20 g air dry or field moist 6 months NEPM
Moisture plastic or glass 20 g field moist 14 days NEPM
Organochlorine pesticides glass 20 g or 1 x 125 mL cool to <4 °C 14 days until extraction, 40 days until analysis US EPA SW-846
Organophosphorus pesticides glass 20 g or 1 x 125 mL cool to <4 °C 14 days until extraction, 40 days until analysis US EPA SW-846
Organotins (tributyl tin – TBT) glass 20 g or 1 x 125 mL cool to <4 °C 14 days NAGD
PAHs glass 20 g or 1 x 125 mL cool to <4 °C 14 days until extraction, 40 days until analysis US EPA SW-846
PBDEs glass 100 g cool to <4 °C 1 year until (1 after) extraction US EPA 1614
PCBs (dioxin-like) glass 100 g cool to <4 °C 1 year until (1 after) extraction US EPA 1668
PCBs glass 20 g or 1 x 125 mL cool to <4 °C 14 days until extraction, 40 days until analysis US EPA SW-846
PFAS (including PFOS and PFOA) HDPE 250 mL jar cool to <4 °C 60 days until (30 days after) extraction US EPA 821-R-11-007
pH plastic or glass 20 g air dry or field moist 7 days NEPM
Phenols glass 20 g or 1 x 125 mL jar cool to <4 °C 14 days until extraction, 40 days until analysis US EPA SW-846
Sulphate plastic or glass 20 g air dry or field moist 28 days NEPM
SVOC (includes pesticides, herbicides, chlorinated hydrocarbons) glass 20 g or 1 x 125 mL cool to <4 °C 14 days until extraction, 40 days until analysis US EPA SW-846
TCLP plastic or glass 50 g as per analyte as per analyte US EPA 1311
TRH (C6–C10)/BTEX glass 20 g or 1 x 125 mL cool to <4 °C, minimise headspace 14 days US EPA SW-846
TRH (C10–C40) glass 20 g or 1 x 125 mL cool to <4 °C 14 days US EPA SW-846
VOCs (includes halogenated aliphatics and aromatics, monocyclic aromatics, alcohols) glass 20 g or 1 x 125 mL cool to <4 °C, minimise headspace 14 days (7 days for vinyl chloride and styrene) US EPA SW-846

References