Is the most sophisticated sample concentration technology available for the analysis of Volatile Organic Compounds in air , soil gas, vapor intrusion or any other gas phase matrices. Entech's exclusive three stage concentration technology is what gives you the power to recover the widest range of compounds regardless of the matrix . Turnkey methods are available for both cryogenic and cryogenless operation to accommodate laboratory and mobile operating environments. This advanced water and CO2 management system provide superior analysis of polar and non-polar organics, while the extended temperature range of heated zones allows recovery of hydrocarbons in the range of C2-C15.

System Hygiene

Cleaning any inlet system is necessary for reproducible results, especially if the inlet is exposed to high concentration samples. Rather than simply flushing lines to remove contaminants, Entech utilizes a vacuum/pressure pulsing technique called VP-Pulse™ that actually pulls contaminants out of un-flushed "dead volumes" so they are not left to slowly diffuse out. This produces blanks in a fraction of the time when compared to constant pressure flushing. The 7100A design eliminates cold regions with absorptive surfaces that can bleed contamination back into the flow stream. These features are critical in obtaining the lowest useable detection limits possible in a wide variety of matrices.

Quality Assurance

The 7100A comes equipped with tools for validating both system and method performance. Routines for system leak checking, matrix spiking and runtime parameter reporting are included. As with Entech's earlier model preconcentrators, the 7100 records critical parameters during sample preconcentration to verify proper system operation. Recorded parameters include trapping flow rates, flow volumes, trap pressure drop, trapping temperatures, water management parameters, desorption temperatures and flows, autosampler position, and sample transfer times. The preserved history of each preconcentration can be used for internal QA or to simply add more credibility to the data, which is especially important if the analytical results are used in litigation.

Matrix Spiking

Calibrating air systems is usually performed using carefully prepared standards in a clean matrix (N2 or zero air). This assumes that no interference exist in actual air samples that will change response factors or detection limits. However, this may not be the case. The true detection limit of benzene, for example, may be altered if it co-elutes with some high-concentration interference that was not in the standard. The only way to determine whether you can "see" your targets in your samples is to spike low levels of your analytical standard right into the actual matrix. The 7100A makes this incredibly easy by providing a place in the sample sequence table to enter a co-preconcentration volume of analytical standard. By adding 1 ppb of target compounds, for example, all responses should go up by about 1ppb. If not, interference may exist. This will add reassurances on the most critical of samples and can help discover problems before data is released.

SmartLabII™ Control Interface

The 7100A is controlled using the Entech SmartLabII™ Control Network. The SmartLabII™ network is capable of controlling an entire air analysis laboratory from a single computer operating under Microsoft Windows® 2000. The 7100A user interface includes screens for developing concentration METHODS, SEQUENCE TABLES, and TASKS for the ultimate in automated, unattended operation. Specialized tasks include routines for pulsed vacuum/pressure cleaning (VP-Pulse™), system leak checking and trap bakeout. During runtime operation, a parameter log is maintained (QA/QC report) which adds reliability and certainty to the generated data. Operation under Windows® allows system operation and vendor support through remote modem communication.

Leak Checking

Leaks are a major source of error in preconcentration systems. The 7100 performs automated leak-checking using either pressure or vacuum techniques to insure that tight system is leak tight before opening valves on canisters or bags, or before exposing tubes to pressurized desorption gas. A report is generated giving a pass/fail indication, as well as the starting and ending pressures. Leak checks can be done either by selecting individual sample ports, or by selecting a sequence table which defines a group of positions on the autosampler.