Improving Headspace Analysis

The need to test for minute levels of gases and vapors in pharmaceutical, biopharmaceutical, and nutraceutical packages is growing, reports Anthony Ahmed, product manager for Mocon Inc. (Minneapolis). “With the advancements in genetics, live medicines with living organisms are now more prevalent,” he explains. “The products have low tolerances for atmospheric influence.”

Mocon has served this market for years with devices that test closed packages for oxygen and carbon dioxide. Mocon’s latest model, the Pac Check Model 650 EC dual oxygen and carbon dioxide benchtop headspace analyzer, targets low-headspace packages. “Single-dose packages such as ampoules, vials, syringes, and blow-fill-seal units frequently have gas headspace of less than one cubic centimeter. Instruments need three to four times that to produce an accurate reading, which means that gas needs to be drawn from multiple packages,” says Ahmed. The new unit can measure both oxygen and carbon dioxide concentration ranges from 0 to 100% in rigid, semirigid, and flexible packages.

Mocon has made its latest instrument more consistent and stable by improving calibration. “Product manufacturers are testing for oxygen and other gases at very sensitive levels, but perhaps not as reliably,” Ahmed says. “When you are testing down to such levels, instruments can become unstable. The Pac Check Model 650 EC self-calibrates to pure, certified gas of a known oxygen content.” It patent-pending calibration feature, Cal-Smart, uses ambient air and advanced electronic controls to perform a two-point calibration (0 and 21.9% gas levels) versus the commonly used room air or certified tank gas methods. “We know that the instrument knows what zero parts per million (ppm) oxygen looks like, instead of misreading 10 ppm as 0 ppm,” Ahmed adds.

Mocon has also built in fail-safe elements that protect the instrument from liquids. “With headspace that small, occasionally a small amount of liquid might be inadvertently removed and inserted into the analyzer along with the gas,” Ahmed says. An advanced filtration system, Flo Smart, blocks liquid by swelling up, sealing off the path to the instrument. If some liquid does get in, it will only reach a section of the instrument that can be replaced at a relatively low cost. “With previous instruments, companies had to spend $3000–$4000 on such damage, whereas now it will only cost about a hundred to fix,” he says. “Some of our customers are changing out their existing units precisely for this fail-safe system.” In many instances, a damaged sensor can be replaced by plant personnel in less than 10 minutes without the additional cost of a service call or significant downtime.

The Pac Check 650EC is the second product launched under Mocon’s Performance Series, EC (electrochemical) class.  The line has been designed as a cost-effective option for smaller companies and fledgling businesses in emerging global economies, which previously could not afford package headspace analysis. “We’ve engineered a true laboratory instrument at a very affordable cost for entry-level companies to determine exactly how much residual oxygen and carbon dioxide has been left inside the package,” says Ahmed.

The Pac Check Model 650 allows both automatic and manual gas sampling.