A qualitative method for detection of peanuts in foods using polymerase chain reaction was developed. A universal primer pair CP 03‐5′/CP 03‐3′ was designed to confirm the validity of the DNAs for PCR. The plant‐specific amplified fragments were detected from 13 kinds of plants using the universal primer pair. In addition, for the specific detection of peanuts with high sensitivity, the primer pair agg 04‐5′/agg 05‐3′ was designed to detect the gene encoding the peanut agglutinin precursor. The primer pair specifically generates a 95‐bp amplified fragment from peanut genomic DNA. Five hundred femto grams of peanut genomic DNA can be detected using the established method. The same qualitative results were obtained from both model processed and nonprocessed food samples containing 0.001, 0.01 and 0.1% of peanut. Moreover, it was shown that the trace amount of peanut in the commercial food products could be qualitatively detected using this method. The reproducibility and applicability of the proposed methods were verified in a six‐laboratory collaborative study.

The electron temperature T e and density N e of atmospheric-pressure non-equilibrium dielectric barrier discharge argon (Ar) plasma are measured with optical emission spectroscopy. Continuum emission due to bremsstrahlung is applied to the analysis of the electron temperature and density with the spectrometric system in the visible wavelength range calibrated absolutely. The assumption of the Maxwellian electron energy distribution function (EEDF) results in T e ≃ 0.29 eV and N e ≃ 1.1 × 1016 cm−3, whereas the Druyvesteyn EEDF leads to the result T e ≃ 0.79 eV and N e ≃ 1.4 × 1014 cm−3. To confirm the validity of these values, several line intensities of the excited states of the Ar atom are observed experimentally and compared with the theoretical population densities calculated by the Ar collisional–radiative (CR) model that includes atomic collisional processes. It is confirmed that the order of the observed excited-state number densities agrees well with that calculated numerically by the CR model with the Druyvesteyn EEDF, while the Maxwellian EEDF gives poor results.

This work is focused on diagnostics of electron temperature (1.0 eV–3.8 eV) and electron density (1.0 × 109 cm−3–5.0 × 1012 cm−3) of low-pressure (133 Pa) discharge argon plasma by optical emission spectroscopic (OES) measurement. The diagnostic method using multi-emission lines was analyzed. First, the excitation-kinetic models were obtained by extracting dominant kinetic processes based on the collisional-radiative model. Then, the diagnostic equations for wide range of electron temperature and density were proposed to describe the approximate excitation kinetic balance of several excited levels. 15 optical emission lines (wavelength range: 340.7 nm–912.3 nm) were selected for OES measurement. RMS of the theoretical relative error was found to be 5.96% for electron temperature, while 32.6% for electron density. The diagnostics of 2.45 GHz microwave plasma was demonstrated by the proposed method and by the probe method. The electron density results by the proposed method were in good agreement with the probe method.

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