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Method Summary

Method Source U.S. EPA National Exposure Research Laboratory (NERL) [formerly EMSL]
Method Number245.1
Revision InformationRevision 3.0, 1994
Method NameDescriptive Name: Mercury by CVAA

Official Name: Mercury (Manual Cold Vapor Technique)

MediaMedia: WATER
SubcategoryInorganic
Citation Methods for the Determination of Metals in Environmental Samples, Supplement 1 (EPA/600/R-94/111)
Method Download Adobe Acrobat (pdf) icon Download full method now (PDF file)
Summary of MethodA sample is digested in a glass bottle for 2 hours with a persulfate/permanganate solution under heating. After digestion, the mercury in the sample is reduced to its elemental form with stannous chloride. The concentration of mercury in the sample is determined using a cold vapor atomic absorption (CVAA) spectrometer system.
Scope and ApplicationThis method allows for determination of total mercury in drinking, surface, ground, sea, and brackish waters, and industrial and domestic wastewaters.
Applicable Concentration Rangeabove 0.2 ug/L
Interferences

(A) Ions and metals: Sulfide, chloride, copper, and tellurium are reported interferences.

(B) Volatile materials: Chlorine and other volatile compounds which absorb in the range of mercury should be purged from the head space of the digestion vessel before the addition of stannous chloride.

QC RequirementsQuality control requirements include an initial demonstration of laboratory capability through analysis of laboratory reagent blanks (LRB), fortified blanks (LFB), quality control samples (QCS), and an MDL study. Ongoing quality control checks include analysis of laboratory fortified matrices (LFM), (laboratory reagent blanks) LRB, and instrument performance check (IPC) samples.
Sample HandlingFor total mercury, preserve samples with (1+1) nitric acid, and hold for 16 hours at a pH < 2 prior to analysis. Samples may be preserved in the field or upon receipt at the laboratory (the latter may minimize the chance of contamination). Use extreme care to minimize sample contamination by checking equipment, and avoiding exposure of the sample to airborne mercury in the laboratory.
Max Holding Time28 days.
Relative Cost/Effort$51 to $200
Sample Prep Method(s) 
 

Method Mercury by CVAA has 1 analytes associated with it.

Analyte


Detection
Level


Bias Precision Pct False
Positive
Mercury
(7439-97-6)
.2 ug/L166 % Rec (ML)89 % RSD (ML).21 ug/L
export_analytes
Precision Descriptor NotesPrecision and accuracy values calculated from interlaboratory data collected at 76 laboratories as part of EPA's method performance studies. Additional data are available in the method.
Detection Level NoteDL is taken as lowest point of the effective range.
 
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