1	Problematic Analytes By Bill Hahn Protocol Analytical, LLC
2	An Open Technical Forum Our goal is to share technical experiences Most labs experience the same issues Few labs share those experiences Too often, analytical methods are strained to perform certain analyses
3	Volatile Organic Problem Children Who do you love………….. 2-Chloroethyl vinyl ether Vinyl acetate Vinyl chloride Chloroprene Acrolein Do we see a pattern??????
4	Polymers / Dimers / Trimers Vinyl is very big on polymerization ….just a little light ……..just a little free radical ………….just a dirty look!
5	Poor Purging Efficiencies Acetone tert-Butyl alcohol Isopropanol Any-old-OL Keep in mind that these pull in water also. Watch out for those Rev. 4 Compounds!
6	Welcome to the world of High Energy The lab world is filled with UV The lab world is filled with Heat The lab world is filled with chemicals High energy causes high reactivity The compounds that we term problematic are all very reactive These compounds don’t have an easily controllable nature Legislation as well as customers require analysis, regardless of the quality of science
7	Analyze with minimal compromise Use fresh standards Blend your standards carefully Stabilize where possible Be sure of your Methanol (we add water) Watch your response factors Use Custom Standards……
8	How about that Acetaldehyde? Remember Dimers? How about Trimers? We see both in Acetaldehyde standards We make these every Monday We have to re-distill the starting material Then we use only the headspace Methanol is the kiss of death……….
9	Acetaldehyde Analysis and Risk Plastic containers must be monitored Many of the lots of plastic containers are failing due to bad standards Many of the standards out there are wrong
10	Acetaldehyde degradation
11	Use Only Fresh Standards Acetaldehyde is already going bad when first made Mix in water only!!!! Store with zero headspace
12	Pentachloroethane Looks great upon direct injection Watch your Tetrachloroethene response! We have observed a breakdown of Pentachloroethane on the trap!!!!!!!!! There is a linear breakdown with time
13	Time vs Response
14	No Sharing, No Changes… These compounds are tough to analyze We would like to put these compounds into large blends but they are not conducive to mixing These compounds are only stable for a short time Don’t be afraid to publish your results Run an analysis to validate your method Print disclaimers and educate clients
15	Semivolatile problem children Benzidines Phenols Solvents Glassware Phthalates Injection ports
16	Freebase vs HCl salts Make sure that you know the true concentration High HCl in Methylene Chloride Stabilizers such as amines Methanol is bad for phenol analysis Reactive compounds love glass!
17	Combining Phenols and BN’s Sounds good, bad idea, chemically speaking…… Phenols act like acids Compounds that extract under basic conditions act like, well…… bases! The resultant clash yields strange chromatography The answer again…. Validate your methods.
18	Clean room techniques for VO’s Prevailing wind around the building VO lab should get the first shot at building air Use Charcoal in Fridges and room Nobody likes Mercaptans The Bleach trick……….. Thanks Lyle… No Methylene Chloride or Acetone allowed! Work quickly and do not leave Methanol open
19	Gasses Boil below -25^o C Speed and accuracy are both critical Work with cold reagents Minimize exposure time Store vials in your coldest freezer with the best seals
20	Weighing Gasses Manufacturers have inconsistencies Don’t use a “sprayed on volumetric” technique Use a sealed vessel (we use mininert valves) Use cryogenics
21	Discussion Please don’t hesitate to share your expertise!!!
22	Thank You! If you would like to discuss these issues in more detail Call Bill Hahn at 1-800-862-0080 Email me at bhahn@prostds.com Visit us on the web at www.prostds.com After a tough day in the lab, we like to Ride! Join us!