Thermo Orion 2111's

D3045R-6L Diisopropylamine[DIPA] for these sodium analyzers.             Thermo Orion 2111LL and 1811EL Retrofitted

The 2111 Series Thermo Orion switches to diisopropylamine, a/k/a/ DIPA, for increased sensitivity, and redesigns the reagent bottle adaptor to accomodate a larger 70mm diameter.  DIPA will raise the pH well above 11 on plant cycle samples.  Run at 25ml / minute you'll get good good pH buffering; and , this can be checked by  measuring the pH after a measurement, and it should be pH > 11. According to Orion, DIPA has been proven to provide better low-level signal stability, and has additional benefits over MEA reagent: Pure Di-isopropylamine (DIPA) Passively diffuses through silicone rubber tubing into sample, the 4-in (10-cm) length of tubing resides in head-space above liquid. MEA required 4 ft (1.33M) of tubing. Constant DIPA vapor pressure assures constant pH over life of reagent. Strength of DIPA as base varies inversely with temperature so pH remains constant even when temperature changes diffusion rate.  DIPA is used to exhaustion so waste disposal is reduced. Lasts 60 days at 25 deg C.

Martek Scout

Martek Instruments provides a Panel Mounted version using the same products described here.

DS&M-Scientific developed independently, a diffusion tubing set-up that is amazingly similar the latest version Thermo Orion.  

Ours is simple with off the shelf components; and, less plastic.

We offer two different kits for the 2111LL reagent bottle adaptor. 

One is for monthly maintenance for one year; the other is for changeover of up to six analyzers.

The monthly maintenance kit also ships with the D3045-6L diisopropylamine (6X0.8L).

According to Thermo Orion in this ThermDTpdf  the diffusion tubing should be changed out monthly. 

Go here to see these products.



Diisopropylamine [IUPAC name | N-isopropylpropan-2-amine] is a colorless, flammable, volatile liquid [19.4O F flash point] with an odor like that of ammonia. Flash point is the lowest temperature at which a liquid can form an ignitable mixture in air near the surface of the liquid. The lower the flash point, the easier it is to ignite the material.[for example, gasoline has a flash point of approximately -40 degrees C (-40 F)].  A closely related and less common term is fire point, the temperature at which the flame becomes self-sustained so as to continue burning the liquid (at the flash point, the flame does not need to be sustained). The fire point is usually a few degrees above the flash point.

The air odor threshold concentration for DIPA is 1.8 parts per million (ppm) parts of air. Vapor pressure at 20 degrees C (68 degrees F): 60 mm Hg.

It is corrosive as well as flammable.  The point being...It is a personnel hazard, as well as a fire hazard.

Diisopropylamine is a severe eye irritant, and exposure to high concentrations is expected to cause pulmonary irritation and edema. Workers exposed to concentrations ranging from 20 to 50 ppm reported haziness of vision.  

Here's a good document to read before handling. DIPA osha.pdf

Another good run-down more from NFPA slant on the  characteristics of diisopropylamine.

The bottle is heavy duty, and coated with PVC for drop/spill prevention.  

Changeout is the goal here.

Some 2111XP Series utilize Ammonium Hydroxide, ACS in a 2L Rectangular Leak-proof Bottle. Two different packages are available depending on the range. 

The difference is in the diffusion tubing kit supplied.