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Environmental Express
• 18
AutoBlock® Fill:
Operation and Instruction Manual
EPA Method 200.8
1.0 Scope and Application
1.1 The following procedures have been written as an aid to EPA digestion
procedure 200.8 for use with the Environmental Express HotBlock. EPA
Method 200.8 is for the determination of total recoverable analytes in
groundwater, surface water, drinking water, wastewater, and (with the
exception of silica) in solid samples such as sediment, sludge and soil. Use
EPA Method 200.8 for reference while following the sample preparation
steps outlined below. A complete list of elements appropriate for analysis is
included in EPA Method 200.8. Analysis can be performed by ICP-MS.
2.0 Apparatus and Materials
2.1 HotBlock for Metals Digestions — Item # C6002, SC100, SC150*, SC151*,
SC154, SC196, SC2015, SC2050, or SC2100*
2.2 Polypropylene Digestion Vessels — 50mL, 100mL, or 15mL
2.3 Ribbed Watch Glasses or Reflux Caps, appropriately sized for vessel capacity
2.4 FilterMate — Item # SC0401 (or appropriate FilterMate® or FlipMate®) for
sample filtration if necessary
* Note: For all procedures, when using the block with the SC490 digestion vials with
a 100mL sample, double the volume of all reagents and acids added.
3.0 Procedure, Aqueous Sample Preparation -- Dissolved Analytes
(EPA Method 200.8, Paragraph 11.1)
3.1 For the determination of dissolved analytes in ground and surface waters,
pipet a 20mL or greater aliquot of filtered, acid-preserved sample into the
polypropylene digestion vessel.
3.2 Add an appropriate volume of (1+1) HNO
3
to adjust the acid concentration
of the aliquot to approximate a 1% (v/v) nitric acid solution. If the direct
addition procedure is being used, add internal standards, cap and mix.
Note: If a precipitate is formed during acidification, transport or storage the sample aliquot
must be treated using procedures for Total Recoverable Analytes.
4.0 Procedure, Aqueous Sample Preparation — Total Recoverable Analytes
(EPA Method 200.8, Paragraph 11.2)
Note: This section applies to water samples containing turbidity of greater than 1 NTU.
4.1 For each digestion procedure, transfer 50mL of well-mixed, unfiltered,
acid-preserved sample into the polypropylene digestion vessel.
4.2 Add 1.0mL (1+1) HNO
3
and 0.5mL of (1+1) HCl and swirl. Heat in the
HotBlock at a sample temperature of 85°C. The HotBlock set temperature
should be approximately 105°C. The temperature of a reference blank
should be tested to ensure correct temperature.
Adaptation for EPA Method 200.8, for use with the
Environmental Express HotBlock® Digestion System
Revised 12.13
