Obie’s Out of Bounds

‘If you don’t read the newspaper you are uninformed, if you do read the newspaper you are misinformed.’
-Mark Twain

Suppose you were an idiot. And suppose you were a member of Congress…. But then I repeat myself.
-Mark Twain

I contend that for a nation to try to tax itself into prosperity is like a man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill

A government which robs Peter to pay Paul can always depend on the support of Paul.
-George Bernard Shaw

A liberal is someone who feels a great debt to his fellow man, which debt he proposes to pay off with your money.
-G Gordon Liddy

Democracy must be something more than two wolves and a sheep voting on what to have for dinner.
-James Bovard, Civil Libertarian (1994)

Foreign aid might be defined as a transfer of money from poor people in rich countries to rich people in poor countries.
-Douglas Casey, Classmate of Bill Clinton at

Civil Libertarian Government is the great fiction, through which everybody endeavors to live at the expense of everybody else. -Frederic Bastiat, French Economist (1801-1850)  Government’s view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
-Ronald Reagan (1986)

I don’t make jokes. I just watch the government and report the facts.
-Will Rogers

If you think health care is expensive now, wait until you see what it costs when it’s free!
-P.J. O’Rourke

In general, the art of government consists of taking as much money as possible from one party of the citizens to give to the other.
-Voltaire (1764)

Just because you do not take an interest in politics doesn’t mean politics won’t take an interest in you!
-Pericles (430 B.C.)  

No man’s life, liberty, or property is safe while the legislature is in session.
-Mark Twain (1866 )

Talk is cheap…except when Congress does it.
-Unknown

The government is like a baby’s alimentary canal, with a happy appetite at one end and no responsibility at the other.
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The inherent vice of capitalism is the unequal sharing of the blessings. The inherent blessing of socialism is the equal sharing of misery.
-Winston Churchill

The only difference between a tax man and a taxidermist is that the taxidermist leaves the skin.
-Mark Twain

The ultimate result of shielding men from the effects of folly is to fill the world with fools.
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There is no distinctly Native American criminal class…save Congress.
-Mark Twain

What this country needs are more unemployed politicians.
-Edward Langley, Artist (1928 - 1995)

A government big enough to give you everything you want, is strong enough to take everything you have.
-Thomas Jefferson

ISOTOPE DILUTION FOR THE ANALYSIS OF METALS IN PLASTICS  Ralph Obenauf, Vanaja Sivakumar, Laszlo Ernyei, Bill Driscoll, SPEX CertiPrep, Inc. 203 Norcross Avenue, Metuchen, NJ 08840, robenauf@spexcsp.com 

     The European Directive, Restriction of Hazardous Substances (RoHS) & Waste Electrical and Electronic(WEEE) restricts the use of hazardous substances such as  lead, cadmium, chromium(VI), mercury and brominated polybihphenyl ethers  in electronic and other equipment.  The RoHS & WEEE directives set only a minimum standard.  Different countries have set their own regulations and requirements.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             Various analytical methods are employed to determine the concentration of restricted substances.  Most methods require some sample preparation such as digestion or extraction.  Many of the methods currently used are not appropriate for all products tested, and results differ from method to method.  It is vital to develop standard methods that produce reliable results that can be implemented by all laboratories.  We have developed a method for accurate analysis of the above metals in plastic.       Methods based on direct analysis of solid samples by XRF and Laser Ablation ICP-MS are limited due to the lack of calibration standards for various complex plastic matrices.  Methods based on destructive sample preparation usually employ heating the polymers with mineral acids or dissolution in organic solvents [1].  However, heating with acids may lead to the loss of analytes due to volatilization and many polymers are sparingly soluble in organic solvents.  Here we employed two techniques for sample preparation, namely, conventional ashing and microwave digestion.       Isotope dilution Mass Spectrometry (IDMS) is based on the addition of a known quantity of an enriched isotope to a sample. Equilibration of the spike isotope with the natural element in the sample alters the isotope ratio that is measured. Knowing the isotopic abundance of both spike and sample, the amount of spike added to the known amount of sample, the measured concentration of the spike added and the altered isotope ratio, then the concentration of the element in the sample can be calculated [2].  Since elements of interest such as Cd, Cr and Pb in the RoHS directive have two or more naturally occurring isotopes, the isotope dilution technique presents an interesting solution for the determination of these elements.       Ashed polyethylene polymer dissolved in nitric acid was analyzed for cadmium, chromium and lead. The polymer was spiked with a known amount of cadmium enriched with Cd-106, chromium enriched with Cr-50 and lead enriched with Pb-206; then ashed.  Both spiked and un-spiked polyvinyl chloride and polyethylene polymers were also digested in a combination of nitric, hydrochloric, hydrofluoric acid along with hydrogen peroxide.     The IDMS technique results in higher accuracies in the determination of lead, chromium and cadmium than conventional calibration methodology.   Partial loss of analyte due to sample preparation or the complexity of the matrix did not affect the accuracy of determination.   

References: 1. Digestion of Plastic Materials for the Determination of Toxic Metals with a Microwave Oven for Household Use: Hiroki Sakurai et al, Analytical Sciences, February 2006, Vol.2.2. USEPA Method 6800: Elemental and Speciated Isotope Dilution Mass Spectrometry. 

Quotes 

“Pain is fear leaving the body.” 

“Whatever Doesn’t Kill You Makes You Stronger.”  Friedrich Neitzche 

“To whom much is given, much is required.”  John F. Kennedy 

“God comes to the hungry in the form of food.”   Mahatma Gandhi 

“They cannot take away our self-respect if we do not give it to them. “   Mahatma Gandhi 

“The journey is the reward.”   Tao Saying 

“If you don’t fail now and again, it’s a sign you’re playing it safe. If you don’t fail now and again, it’s a sign you aren’t aiming high enough.”    Woody Allen 

“There is neither happiness nor misery in the world; there is only thecomparison of one state with another, nothing more. He who has felt thedeepest grief is best able to experience supreme happiness. We must havefelt what it is to die, Morrel, that we may appreciate the enjoyments ofliving.” - Alexandre Dumas – “The Count of Monte Cristo” 

“We boil at different degrees.”   Ralph Waldo Emerson. 

Blowing out another’s candle will not make yours shine brighter. 

I refuse to engage in an intellectual battle with an unarmed man. 

Matrix effects in ICP-AES analysis

Ralph Obenauf and Vanaja Sivakumar

SPEX CertiPrep, Metuchen, NJ www.spexcsp.com

The sample “matrix” is the bulk composition of the sample such as water, organic compounds, acids, dissolved solids and salts, etc. Matrix effects can influence the ability of an analytical method, to qualitatively identify and quantitatively measure target compounds in environmental and other samples, by indirectly affecting the intensity and resolution of observed signals. To obtain defensible results the analyst must account for all matrix effects. In ICP-OES analysis the ionic-to-atomic line intensity ratio can be used as an indicator for determining plasma related matrix effects. Elements such as sodium and calcium, which are ubiquitous in nature, have low ionization potentials and as a consequence are some of the most easily ionized elements. In this study the influence of sodium as well as the acid concentration on the ionic-to-atomic intensity ratio of chromium, cadmium and lead has been investigated.

Effect of Sodium concentration:

We observed a considerable change in the recovery of cadmium and chromium, which exhibits a profound influence on these analytes by varying the concentration of Sodium. The relative intensity of chromium and cadmium atom lines were much higher than the respective ionic lines for these analytes. The effect is significant even at 50 ppm sodium. The lead concentration is affected, relatively, less by the change in the sodium concentration.

Effect of acid concentration:

The matrix effect due to changes in the acid concentration was very significant for cadmium and lead in nitric acid, While the chromium atomic line was unaffected, a decrease was observed in the in intensity for the chromium ionic line. The higher the acid concentration, the lower the intensity for lead and cadmium, and therefore resulting in poorer detection limits. We observed much smaller changes in analyte recoveries for increases in hydrochloric acid concentrations when compared with comparable nitric acid concentration changes.Matrix effects have a profound effect on the accuracy of trace elemental analysis by ICP. Excess acid from acid digestion can be a source of error in the analysis. Because of the different behavior of the atomic and ionic lines, at least two internal standards are needed to compensate for matrix effects. It is absolutely essential to match the sample matrix to the standard to assure accurate and defensible data. www.spexcsp.com

Red Wine Color Chemistry   Ralph Obenauf, SPEX CertiPrep,

The table below lists the approximate calories in an average (115ml or 4 oz) glass of wine. Wine can contain up to 15% alcohol by volume and alcohol contains 7 calories per gram. The more alcohol a wine contains the more calories, obviously. For comparison, on average, the same 115ml of beer has 50 calories, light beer 37 calories and non-alcoholic beer 20 calories, but no one I know stops at 115ml. Note that one gram of fat contains 9 calories and soda….forget it. I think I switched to wine to lose weight, dry red of course. Find more information on beer at: www.brewery.org/library/

Ralph Obenauf, PhD SPEX CertiPrep, Metuchen, NJ 08840, ROBENAUF@SPEXCSP.com 

www.SPEXCSP.com  

Abstract

Certified values of Reference Materials (CRM) are not useful unless accompanied by a stated and precisely defined uncertainty.  If certificates of analysis are examined, one often finds inconsistencies, misstatements and errors related to uncertainty (dispersion of the value that could reasonably be attributed to the measurand) and stability (change in value over time).  A precise understanding of measurement uncertainty on the part of the user is required as well as confidence that the reported uncertainty is calculated and defined correctly.  Your measured values are only as good the uncertainty of those results. 

 The paper will cover the evaluation of the total expanded uncertainty arising from all sources and covering all processes involved in determining the certified value of an ICP CRM.   This determination will be for a chromium (VI) reference material whose certified value was determined by titration against a standardized sodium thiosulfate solution which was in turn standardized against a potassium dichromate standard reference material, SRM.  Chromium (VI) is one of the six substances listed in the EU RoHS (Restriction of Hazardous Substances) directive 2002/95/EC requiring electronic equipment producers to limit these substances in their products.   

The above method was selected for discussion as it contains examples of many of the common procedures used in analytical determinations, wet or instrumental.  Therefore the uncertainty calculations here can be directly applied to other analytical methods to determine the statistical uncertainty of other common laboratory measurements such as those by ICP and ICPMS.