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WonderAnalytical chemistry fact

Mass spectrometry reveals what a sample is made of by weighing its molecules. It gives them an electric charge, sorts them by mass and counts them, and the resulting pattern can identify drugs, pollutants, isotopes and proteins.

Mass spectrometry

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The story behind the card

An ion source gives atoms or molecules an electric charge, turning them into ions. An analyser sorts them by their mass-to-charge ratio, for example by how far a magnet bends them or how long they take to fly down a tube, and a detector counts what arrives. J. J. Thomson built an early version in 1912–13 and found that neon atoms come in two different masses, the first sign of isotopes in a stable element. Francis Aston developed it into the mass spectrograph in 1919 and won the 1922 Nobel Prize in Chemistry. Gentler ways of charging molecules, developed in the 1980s, let the method weigh whole proteins and earned John Fenn and Koichi Tanaka a share of the 2002 Nobel Prize in Chemistry. Today it is used in doping tests and newborn screening.

Türkçe oku
Kütle spektrometrisi, bir örneğin nelerden oluştuğunu moleküllerini tartarak ortaya çıkarır. Molekülleri elektrikle yükler, kütlelerine göre ayırır ve sayar; ortaya çıkan desenden ilaçlar, kirleticiler, izotoplar ve proteinler tanınabilir.

İyon kaynağı atom ya da moleküllere elektrik yükü vererek onları iyona dönüştürür. Analizör bu iyonları kütle/yük oranlarına göre ayırır; örneğin bir mıknatısın onları ne kadar saptırdığına ya da bir tüpte ne kadar sürede yol aldıklarına bakar. Dedektör de ulaşanları sayar. J. J. Thomson 1912–1913'te ilk örneklerden birini kurdu ve neon atomlarının iki farklı kütlede bulunduğunu gördü: Kararlı bir elementte izotopların varlığına dair ilk işaret buydu. Francis Aston aygıtı 1919'da kütle spektrografına dönüştürdü ve 1922 Nobel Kimya Ödülü'nü aldı. 1980'lerde geliştirilen, molekülleri parçalamadan yükleyen yumuşak yöntemler bütün proteinlerin tartılmasını mümkün kıldı; John Fenn ile Koichi Tanaka bu sayede 2002 Nobel Kimya Ödülü'nü paylaştı. Bugün doping testlerinde ve yenidoğan taramalarında kullanılır.

Sources and further reading

Background reading: Mass spectrometry
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