Sample Preservation

The aim of correct environmental sampling is to maintain the integrity of the sample from it being taken in the field to being analysed by the laboratory. In order to achieve this it is necessary to preserve in the field for some analytes as they can degrade and change during the transport period. If samples are not presented in the correct containers, with preservatives if applicable, the result may not be accredited.

Soils

Chemical preservation of soil is usually not recommended. Sampling into the correct containers and cooling is the best approach. Plastic tubs are recommended for sampling soils for inorganic analysis, metals, pH, cyanide, sulphide, sulphate. Amber jars are recommended for organics. The amber glass protects from the UV light which can chemically degrade some species. Organic compounds do not react with glass but they do have a tendency to sorb to plastics. Sample volatiles into a 60ml amber jar.

Waters

The chemical preservation of waters is recommended for some analytes together with the use of correct containers and cooling.

Cyanide

The sampling bottle for cyanide contains a sodium hydroxide pellet to keep the water alkaline and the cyanide in solution. If the water is not preserved and is slightly acidic, the cyanide may convert to hydrogen cyanide gas and be lost from the sample.

Sulphide

Sulphide oxidises to sulphate as soon as it meets the oxygen of the atmosphere. It is preserved with a SAOB (sulphide anti oxidant buffer) which fixes the sample for transportation.

Dissolved Metals (filtered in the field only)

Sample into nitric acid after filtration to prevent hydrolysis to insoluble oxides. Our methodology also allows accreditation for samples filtered and acidified in the laboratory.

Ferrous iron

Sample into a bottle containing hydrochloric acid to prevent the ferrous iron oxidising to ferric iron. Total iron can also be taken from this bottle.

Manganese II

This requires filtering to remove insoluble MnIV compounds before adding to a bottle containing hydrochloric acid. The acid prevents oxidation of MnII to insoluble MnIV. BOD/COD/Dissolved oxygen (Dissolved Oxygen should ideally be measured in the field) Fill one litre to the brim to exclude any oxygen. Keep cool to prevent uptake of oxygen and reduce bacterial activity. Return to the laboratory as soon as possible.

Organic analytes

Generally no preservation is required but it is necessary to sample into amber glass bottles and keep cool. Sample volatiles (VOCs, BTEX, GRO, C5-C10 of CWG) into a 40ml vial with no headspace.

Inorganic analytes

Apart from the analytes detailed above, these can be sampled into plastic bottles with no preservation. Our results, no matter how accurate and precise the testing, depends entirely on correct field sampling, packaging and returning to the laboratory as quickly as possible after the sampling event.

For further information about Environmental Scientifics Group and our services, please contact us

Registered office: ESG House, Bretby Business Park, Ashby Road, Burton on Trent, DE15 0YZ. Incorporated in England: 02880501 | Disclaimer | Developed by DDME | Design by Carrick

News

Tuesday 22 November 2011

ESG awarded an industry first with glowing references

ESG become the UK’s first company to gain UKAS accreditation for maintained load testing Environm...

Thursday 03 November 2011

ESG achieves 12 months without a reportable or lost time accident

Environmental Scientifics Group (ESG), the UK’s leading environmental compliance and fo...

Friday 21 October 2011

ESG Henley Water is ‘Supplier of the Year’ finalist at Norland Supply Partner Event

‘Highly commended’ status awarded by Norland contract manag...

Tuesday 04 October 2011

ESG offers enhanced asbestos services

Full UKAS accredited quantification service for analysing asbestos in soils and aggregates saves time and money 03 Octo...

Monday 03 October 2011

ESG helps premiership rugby club to stay on top

Bedwas Rugby Club retain coveted place and provide fans with additional standing 03 October 2011 – Envi...

Thursday 29 September 2011

ESG appoints Group HR Director

Environmental Scientifics Group (ESG), the UK’s leading provider of testing, inspection and compliance services is please...

Wednesday 28 September 2011

ESG expands food testing capabilities

Next-day nutritional chemistry testing service launched Environmental Scientifics Group (ESG), the UK’s leading p...

Thursday 07 July 2011

ESG acquires Leeds-based microbiological laboratory, PMS Micro Limited

ESG extends range of services for its Food Division and provides access to new markets ...

Thursday 07 April 2011

MP for South Derbyshire, Heather Wheeler opens new ESG superlab

State of the art facilities provide unrivalled analytical and laboratory testing services En...

Wednesday 06 April 2011

ESG joins Nuclear Industry Association

Supporting developments throughout the industry lifecycle Environmental Scientifics Group (ESG), the UK’s leadin...

More...

Testimonials

ESG through its Soil Mechanics brand were set a tough challenge by RWE npower and met it full on. From the engineer's perspective, it was evident from the start that many parts of the business would need to pull together to achieve the client's demanding programme. Pembroke in November was never going to be easy, but staff on site, in Bridgend and in the labs demonstrated a team commitment to match and on occasions exceed the client's expectations.

RWE npower