October 2011 Coffee Talk: A Topic Close to the Heart of Dr. Ameika By Julie Higgins, Environmental Express Technical Sales Representative James A. Ameika, FD, FACS and his wife Karin have been the owners of the 21-acre Kona Cloud Coffee Estates on the big island of Hawaii for 14 years. The beans are grown there and roasted in Jonesboro, AR, where Dr. Ameika maintains Come See Us On The Roa d! his “day job” as a Cardiothoracic and Vascular Surgeon. The following is a ur technical sales staff will be traveling breakdown of the fascinating medical aspects of coffee as shared by Dr. Ameika. to shows and events in the next few O months. Scheduled events are listed he coffee bean is party here, as decaf on our website at: envexp.com/conferences comprised of several drinkers do not show this T types of compounds, trait. Our Monday Gulf Coast Conference including carbohydrates morning’s best friend is October 11-12 (50%- mainly sucrose, also known to stimulate Galveston, TX depending on ripening and lipolysis, or the breakdown www.gulfcoastconference.com which species of coffee of triglycerides into fatty FSEA Conference plant), proteins (10-13%) acids, and may be of use October 27-28 and a few other to endurance athletes as a West Palm Beach, FL components, such as way to increase fatty acid www.fsea.net alcohols and alkaloids like metabolism, generating Radiobioassay & Radiochemical xanthines, including much needed energy Measurements Conference everyone’s favorite: during an event. Although October 31-November 4 CAFFEINE! it is a known appetite Destin, FL Let’s focus on the health suppressant, the long term www.rrmc.com effects of these smaller components. First, the effects of caffeine on one’s weight remains alkaloid, trigonelline, has been shown to prevent unknown, so it might still be best to use it as a Professional Conference on Industrial cavities due to its apparent ability to hinder boost during the big race rather than to eliminate Hygiene November 5-8 Streptococcus mutans from adhering to teeth. the physical activity altogether. Baltimore, MD Caffeine makes up 1-2% of the dry weight of the Finally, caffeine has taken the blame for www.pcih2011.org coffee bean, depending on the species, and does increased cholesterol, but there is no evidence to more than clear that morning fog. The amount of back this claim. While some coffee drinkers caffeine in your morning cup of Joe depends on display elevated cholesterol levels, it is actually how that cup was prepared. Xanthines, including the alcohols, cafestol and kahweol, in coffee that caffeine, are known to be smooth muscle have been implicated. On the other side of the relaxants and are often given to asthma coin, these alcohols have been shown to be patients. Caffeine is also administered to anti-carcinogenic in animal studies. These newborns with apnea. Yes, even little ones have components are removed when a coffee filter “Kona Coffee has a richer flavor than a need for caffeine. is in use, so you might want to keep that any other, be it grown where it may, and Clot-busters? Regular coffee drinkers have French press after all! So at the end of the call it by what name you please” been shown to have increased rates of day (or the beginning), it seems that this - Mark Twain fibrinolysis, or the breakdown of clots in the morning vice so many of us know and love body. It is thought that caffeine is the responsible does more than just perk us up! ENVIRONMENTAL EXPRESS www.environmentalexpress.co m ■ cal l 800.343.5319 or 843.881.6560 EXPRESS NEWS 1 Cyanide: The Molecule and its Analysis A Simple Compound with Complex Problems By Edward F. Askew PhD, Askew Scientific Consulting Part 4: Visible Spectroscopy of the Köenig Reaction Products his fourth part of the cyanide series focuses on the Köenig reaction color development of the cyanide sample and its quantitation by visible T spectroscopy. In the previous part of this series, the requirements for cyanide distillation were covered. To review, that process relies on the volatility of hydrogen cyanide gas in a refluxing acidic aqueous solution that is then transported with a stream of air and collected in a sodium hydroxide solution as sodium cyanide salt. Once the distillation has been completed, the cyanide salt in the hydroxide solution is then reacted through a 3-step process to produce a magenta colored solution whose concentration is measured by visible spectroscopy. Reaction The reactions steps as per 4500 CN- E in Standard Methods for the Examination of Water and Wastewater (Eaton 2005) are: 1 Addition of an acetate-acetic acid buffer to maintain a constant pH of 4.5. Figure 1: Köenig Reaction 2 Addition of Chloramine T to selectively chlorinate the cyanide to form laboratories analyzing by this process. Review of the past EPA cyanide cyanogen chloride. Then react the cyanogen chloride compound with method 335.2* (EPA 1980) and the current Standard Methods 4500 CN- E pyridine to open the pyridine ring and form a di-aldehyde under acidic cyanide method shows a time requirement or window needed for the conditions. magenta color to develop and remain stable. (*: EPA method no longer 3 The di-aldehyde then reacts with 2 equivalents of barbituric acid to approved for regulatory compliance under 40 CFR Part 136) form the final Köenig compound through an aldol condensation. The EPA 335.2 method requires: “Allow 8 minutes for color development But, there are inconsistencies in the final concentrations seen by then read absorbance at 578 nm in a 1 cm cell within 15 minutes .” Köenig Scan with Respect to Time 150 PPB Cyanide Figure 2: Stability and Molar Absorbance with Respect to Time of the Koenig Product (3 minutes to 15 minutes) EXPRESS NEWS 2 Köenig Scan with Respect to Time 150 PPB Cyanide Figure 3: Stability and Molar Absorbance with Respect to Time of the Koenig Product (3 minutes to 15 minutes) The Standard Methods method 4500 CN- E requires: “Add 5 mL pyridine- negatives for samples developed and measured outside of the 15 minute barbituric acid reagent, dilute to volume with distilled water, mix thoroughly, maximum time. and let stand exactly 8 min . Measure absorbance against distilled water at More importantly, if the standards are read too early or too late, the low 578 nm.” absorbance readings will impact the slope of the calibration line. This This time requirement for a stable compound or intermediate to form shallower slope may cause the calculated cyanide in a sample to appear within the timeframe of 8 to 15 minutes is supported by previously reported higher that what it actually is. This can lead to false positives being reported observations (Chien, Chang et al. 1980; Ma and Liu 1992) and spectroscopic by the laboratory data collected for this article. Conclusion Ma measured an initial aldol condensation intermediate in the Köenig The useable analysis time window of 5 minutes to 15 minutes is not reaction that had a wavelength maximum at 494 nm. The absorbance clearly indicated in the Standard Methods 4500 CN- E, but is clearly maxima from this intermediate decreased rapidly over 3 minutes, while the prescribed in the older EPA method 335.2. What this means to the laboratory peak at 580 nm grew in. After 5 minutes, the secondary aldol condensation analyst and manager is that the color development step is critical to the intermediate peak at 580 nm was the dominant peak. This is the peak** that accurate determination of cyanide. The use of any instrument from a flow is measured in the Standard Methods and EPA cyanide method. (**: 578 nm injection analyzer to a discrete analyzer or even a manual spectrophotometer in the methods) will require the following checks to be put in place in the laboratory’s Chien measured a more stable product that appeared over a longer period method/SOP: of time (~ 20 hours) in the Köenig reaction. This more stable product had an 1 Scan a developed sample to determine the absorbance maximum. In absorbance maxima that appeared at 490 nm as the secondary aldol the EPA and Standard Methods cyanide methods, the absorbance condensation peak at 580 nm decreased. maxima is given as 578 nm. But on the spectrometer used in this study, These absorbance changes due to the intermediates are confirmed with it was 580 nm. This slight variation is instrument dependent and must analytical results summarized in Figures 2 and 3. be corrected for in the laboratory method/SOP. The Köenig reaction product reached a maximum molar absorbance at 5 2 In the laboratory’s method/SOP clearly state the allowable time minutes after the addition of the final reagent and remained at this high level window (5-15 minutes) for developed cyanide sample measurement. for 15 minutes total. After 15 minutes had elapsed, the absorbance This will make sure that the last sample in a batch is measured within decreased and a new peak appeared at 488 nm. The raw absorbance around the allowed time window. the 580 maximum peak are summarized in Table 1. 3 For discrete analyzers and flow injection analyzers, measure the total The percentage of the 580 nm peak at each time interval compared to the development time for the sample to make sure that development and maximum absorbance at 10 minutes is summarized in Table 2. absorbance measurement happens in the correct time window. Table 2 shows that the decrease in peak height after 15 minutes will be 4 Make sure that the standards and samples are developed and analyzed significant for cyanide analysis at lower concentration.