The MERX-T-DP Automated Total Mercury System for EPA 245.7 is a rugged, extremely fast, sensitive tool for mercury measurements, with low capital and operating costs. It offers vastly better sensitivity, lower detection limits, and higher precision than atomic absorption-based systems at a comparable price. The MERX 245.7 system has a wide linear range, from 1 to 4,000 ng/L in a 25 mL sample, and a detection limit of 0.3 ng/L. Its carryover is less than 0.05%. Because it operates on a discrete sample basis instead of by continuous flow, it has no costly peristaltic pump to maintain and consumes minimal amounts of reagents. This makes it one of the least expensive systems to operate.

Increasingly stringent mercury regulations have made old analytical methods based on atomic absorption, such as EPA 245.1 and 245.2, obsolete. To comply with current wastewater discharge permit requirements, many environmental testing laboratories are upgrading their capabilities to satisfy the lower required detection limits by implementing EPA 245.7. This method uses an atomic fluorescence spectrometer, which is considerably more sensitive, has better linearity, and has a more stable baseline than an atomic absorption spectrometer.

We understand that bench space in modern analytical laboratories is scarce. This is why the MERX 245.7 Gas Flow Control module is designed to sit underneath the autosampler, giving the system a very small bench footprint. Additionally, because the samples are kept in sealed vials throughout the analysis, there is very little risk of contamination.

System includes the following modules: MERX Autosampler, MERX Total Hg Purge & Trap Module, Model III CVASF Detector. Click here to purchase modules separately.

Key Features

• Specifically designed for US EPA Method 245.7
• Less than 1.5 minutes per analysis
• Instrument Detection Limit: <0.3 ng/L
• Working Range: 0 – 100,000 pg
• Run to Run carry-over: <0.05%
• Compatible with Argon, Nitrogen, or Air (dependent upon sensitivity requirements)
• Modularity allows easy conversion to Total Hg by US EPA Method 1631 or Methyl Hg by US EPA Method 1630 in less than 5 minutes.
• Reduced contamination – The biggest challenge to performing quality ultra-low-level mercury analysis is avoiding contamination. MERX greatly reduces sample contamination in two key areas:
• Carryover contamination – By purging samples in the vials, only gaseous elemental mercury is transferred from the vial, through an inert transfer line, to the detector, vastly reducing carryover contamination. Most other systems struggle with carryover contamination due to the use of a common pump, transfer line, and gas-liquid separator.
• Atmospheric contamination – Utilizing sealed sample containers on the autosampler prevents atmospheric mercury from contacting the sample. Other systems have open vials and must be operated in a clean room environment.
• Reduced reagent consumption – Rather than requiring a continuous flow of reagents common to most other systems, MERX uses only the necessary amount of reagents to effectively reduce a sample, minimizing reagent and waste disposal costs.
• Less maintenance – In addition to syringe and peristaltic pumps being a huge source of cross contamination, these pumps generally require constant maintenance and tubing replacement. With the pump-free MERX system, these issues simply don’t exist.