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Vacuum Distillation


SW-846 Method 8261A
SW-846 Method 5032
SW-846 Method 8260C
PATENTS
REFERENCES

1,4 DIOXANE
VOC's in Milk
VOC's in Soil
TRAINING
VACUUM DISTILLATION
ADVANTAGES OF VACUUM DISTILLATION
SUPERFUND EVALUATION
INTERNAL STANDARDS FOR METHOD 8261
 
 

ADVANTAGES OF VACUUM DISTILLATION OVER PURGE & TRAP / HEADSPACE & THERMAL DESORPTION TECHNIQUES


Vacuum Distillation

P&T/HEADSPACE/T DESORB

The highlight & basis of the method is that it provides a procedure that corrects the raw data for matrix effects and provides associated error criteria for each and every analyte detected.

Biggest drawback of these techniques is that they cannot provide matrix correction of the data, in spite of all the “method modifications” developed over thirty years.

In many cases, to obtain adequate recoveries, the samples are heated – which could have adverse consequences on their chemistry.

Vacuum Distillation technique and the EPA approved instrument –VDC1012 – can run either Method 8261A or the old standby Method 8260C (using 5032)

Equipment cannot run Methods 8261A or 5032.

Using this technique, 1, 4-Dioxane can be routinely analyzed along with all other VOCs without having to do any method modifications.

The associated method requires two separate GC/MS runs to detect 1,4-Dioxane and other VOCs. One run in SIM mode, and the other in normal mode for other VOCs. In spite of this, 1,4-Dioxane results are highly unreliable using these techniques.

This technique is appropriate for analyzing Polar compounds and some svoc compounds that have boiling points below 245C and partition coefficients below 15,000.

These techniques do not give adequate recoveries for Polar compounds and have poor purging efficiencies on many other volatiles. Cannot detect many of the compounds that are detected by Vacuum Distillation.

This technique greatly minimizes foaming of samples and has very minimal problem analyzing soaps etc. in a routine manner.

Foaming samples foul up the system and shut the system down, in spite of using accessories such as “foam sensor” & “foam buster”. Sometimes fritless spargers are used which reduce purging efficiency.

User can mix different matrices in one sample batch & analyze them without any method modification.


NOT POSSIBLE

Just one instrument calibration is all that is required, regardless of sample size or matrix type.

Instrument RECALIBRATION required if ether sample size or matrix type changes.

This technique predicts analyte recoveries using a theoretical relationship between analyte boiling points and water-to-air partition coefficients.

NO SUCH THEORETICAL RELATIONSHIP EXISTS. The recoveries are assumed to be the same as the nearest internal standard. So, user is forced to accept whatever results the test conditions produce, even if they are faulty.


Vacuum Distillation

P&T/HEADSPACE/T DESORB

Eliminates the need for matrix spike and spike duplicates

REQUIRES matrix spike and spike duplicates.

Does not require adsorbent traps. Instead uses cryogenic cooling to trap analytes.

Adsorbent traps used in these techniques are prone to fouling and is the cause of many instrument problems.

This technique has built in QC for every sample tested.

These techniques have surrogates and “windows” of recovery. If surrogates exceed these windows, sample dilution may be required.

Surrogate Matrix Correction software provides the following benefits:

  • Saves analyst’s time & makes data reporting to a customer, very easy.

  • Each report, in addition to analyte recoveries, also provides data accuracy for each analyte.

  • Provides data printout in a CLP format as required by RCRA & SUPERFUND programs.





NO SUCH SOFTWARE CAPABILITY

This technique can handle every matrix type and can analyze a whole suite of volatiles, polar and semi-volatiles – using just one method (8261A)


  • 1,4-Dioxane analysis from ground water & soil samples

  • Waste water, foaming samples and samples with organic content

  • Petroleum contaminated soils, sludge and sediments

  • Oil, waste oil & oily samples

  • VOCs from milk, dry food goods & beverages

  • VOCs from plastics and polymers

  • VOCs from fish tissue and other biota

  • VOCs from leaves, pine needles and other vegetation

  • MTBE and other Oxygenates

  • Essential oils from spices


No method modification is required.

Requires the following methods depending upon the matrix and groups of analytes:


Method 8260 – General VOC analysis(GSMS)

Method 8260 Modified – 1,4-Dioxane by SIM

Method 8015 – non-halogenated volatiles

Method 8021 – aromatic halogenated vocs

Method 5021 – volatiles by headspace

Method 5030 – P&T for aqueous samples

Method 5035 – P&T for solid materials

Method 5041 – Volatiles in air samples

Method 1624 – Volatiles by ID GC/MS


These techniques require Method modifications and method verification studies to address different matrices.



Cincinnati Analytical Instruments