Dataset: Speciated Atmospheric Mercury Fractions

Methods

The methods followed in the creation of the dataset, including description of field, laboratory and processing steps, and quality control procedures

Past Methods (No longer in use)

• Overview
  Started: 2009-01-01
  Ended: 2016-01-04

  The Tekran 2537 system measures mercury concentration using cold vapor atomic fluorescence spectroscopy (CVAFS).

  Instrumentation: Tekran 2537 analyzer; Tekran 1130 sampler; Tekran 1135 sampler; Campbell Scientific CR3000

  Software: Tekran 2537 analyzer program; Campbell Scientific LoggerNet
• GEM collection
  Started: 2009-01-01
  Ended: 2016-01-04

  During the first 2 hours of operation, the Tekran 2537 measures the concentration of gaseous elemental mercury (GEM). These measurements are made directly and are presented as 5-minute averages. Each average results from the operation (i.e. collection and analysis) of one of two cartridges that operate in alternating fashion.

  Instrumentation: Tekran 2537 analyzer; Tekran 1130 sampler; Tekran 1135 sampler; Campbell Scientific CR3000

  Software: Tekran 2537 analyzer program; Campbell Scientific LoggerNet

  Quality Control Measures: As alternating cartridges are used for the measurements, cartridge bias is evaluated as part of data validation
• GOM and PBM Adsorbtion
  Started: 2009-01-01
  Ended: 2016-01-04

  Gaseous oxidized mercury (GOM) and particulate-bound mercury of mean diameter less than or equal to 2.5 µm (PBM2.5) are adsorbed onto prepared glassware in the Tekran 1130/1135 speciation modules for two hours while simultaneously, the Tekran 2537A is analyzing gaseous elemental mercury (GEM) by drawing ambient air through the system.

  Instrumentation: Tekran 2537 analyzer; Tekran 1130 sampler; Tekran 1135 sampler; Campbell Scientific CR3000

  Software: Tekran 2537 analyzer program; Campbell Scientific LoggerNet
• Desorbtion
  Started: 2009-01-01
  Ended: 2016-01-04

  After this two hour period, the system desorbs the glassware by heating the glassware in the speciation modules until the PBM2.5 and GOM are converted to gaseous elemental mercury which can then be detected by the 2537A. During this desorption, the system pumps zero air through the speciation modules so that no ambient air (which could contain mercury) is in the system. After one hour of desorption, the system returns to detecting GEM in ambient air.

  Instrumentation: Tekran 2537 analyzer; Tekran 1130 sampler; Tekran 1135 sampler; Campbell Scientific CR3000

  Software: Tekran 2537 analyzer program; Campbell Scientific LoggerNet

Dataset Fields

Detailed documentation of the fields comprising the dataset, including the type of measurement, units where applicable, and any controlled vocabularies or code lists present in the data

Sampling Equipment

Equipment and software used to collect data, including how that equipment was used.

Past Sampling Equipment (No longer in use)

• Mercury analyzer, data logger
  Started: 2009-01-01
  Ended: 2016-01-04

  Software consists of Tekran 2537 analyzer program and Campbell Scientific LoggerNet

• Mercury analyzer, sampler, micrologger
  Started: 2009-01-01
  Ended: 2016-01-04

  Tekran 2537 analyzer; Tekran 1130 sampler; Tekran 1135 sampler; Campbell Scientific CR3000

Site Characteristics

The spatial extent of the dataset site coverage, and descriptions of the spatial extent and context for the data collection

• Site Description

  West slope of Mount Mansfield in an open field at the Proctor Maple Research Center. Site has a west aspect and an 8% slope

  Minimum Altitude: 399 meters

  Maximum Altitude: 400 meters