4551A Purge-and-Trap Water Autosampler

Improve sample accuracy and save lab counter space with the Model 4551A Water Autosampler. Designed to work with our 4760 Eclipse Purge-and-Trap Autosampler, the 4551A automates VOC analysis for up to 51 clean or lightly particulated water samples.


The extremely compact 4551A Water Autosampler fits strategically under the 4760 Eclipse to save bench space. The instrument precisely transfers water samples from standard 40-mL volatile organic analysis (VOA) vials to the sparge vessel of the 4760 Eclipse for purging. A removable spiral autosampler tray holds 51 sample vials for fully-automated operation. Our optional LV-20 Standards Addition Module adds internal standards, surrogate or matrix spike standards, and reduce the volume of standards used.

Principle applications include: drinking water, wastewater, pharmaceutical, 16+ USEPA-approved methods, VPH and GRO, THMs, BTEX, Geosmin and 2-MIB.

Model 4551 Features:

  • Automated VOC Analysis of up to 51 water samples
  • Compact! Fits directly under the 4760 Eclipse Sample Concentrator
  • Transfers water samples with light particulates (<100 µm) without clogging the system
  • LV-20 Standards Addition Module (optional) automates addition of internal or surrogate standards
  • Program multiple rinses and blanks for maximum sequence flexibility
  • Decrease maintenance downtime and costs – no XYZ arm
  • Peristaltic pump and sample loop eliminate slow syringe drives
  • Fastest VOC autosampler available
4551A 46 cm H x 40 cm W x 42.6 cm D
(18.11 in H x 15.75 in W x 16.77 in D)
4551A and Eclipse

94.9 cm H x 40 cm W x 42.6 cm D
(37.36 in H x 15.75 in W x 16.77 in D)

Depth with Cover 53 cm (20.86 in)
4551A 16.3 kg (36 lb)

4551A and Eclipse
 32.6 kg (72 lb)
Sample Loop  
5 mL

Glass loop (standard)

Valve Six-port electrically actuated, 12 VDC, Valco® Cheminert®

Sample Transfer Pathway


Sampling Needle

7", two-hole, stainless steel
PEEK® Tubing 1/16" O.D. x 0.040" I.D. x 17" 
Nickel Tubing 1/16" O.D. x 0.040" I.D. x 26"



Directive 89/336/EEC:1989
CISPR 11:1990/EN55011 (1991) Group 1 Class A
IEC 801-2/EN61000-4-2
IEC 801-3/EN61000-4-3
IEC 801-4/EN61000-4-4

12 months parts and labor

Sample Transfer


Accuracy Better than ±0.3%
Power Requirements


Voltage 100-230 VAC±10% (autoselecting)
Frequency 50/60 Hz
Gas Requirements


Purity 99.999% (UHP) He or N2
Pressure 50-125 psi
Water Supply

Clean water free of VOCs for rinsing the sample pathway and running blanks