A method for identifying converters from tobacco seedling population. The method includes: 1) sowing and cultivating tobacco seeds to be identified for 45-55 days; sampling a plurality of leaf disks from each of 45-55 days old seedlings; 2) incubating the plurality of leaf disks of each seedling in a sealed container at 37° C. for 10-12 hours, thereby obtaining a plurality of incubated tobacco leaves of each seedling; 3) immersing the plurality of incubated tobacco leaves of each seedling in an extractant, extracting alkaloids and obtaining an extract of each seedling; 4) analyzing the amounts of nicotine and nornicotine in the alkaloids extract of each seedling; and 5) automatically recognizing peaks of the alkaloids extract of each seedling, and calculating the percent nicotine conversion (PNC) and the pseudo percent nicotine conversion (PPNC).

A method of analyzing phenylhydrazine content in a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient includes obtaining a first measured value by measuring a phenylhydrazine content of a standard solution including phenylhydrazine or a salt thereof, a first acidic water and a first water-soluble organic solvent and having a phenylhydrazine concentration of 0.01 μg/mL to 10 μg/mL, obtaining a second measured value by measuring a phenylhydrazine content in a sample solution including a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient, a second acidic water and a second water-soluble organic solvent, and detecting a phenylhydrazine content in a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient based on the first measured value and second measured value. The first acidic water includes hydrochloric acid, the first water-soluble organic solvent is acetonitrile and/or methanol, the second acidic water includes hydrochloric acid, and the second water-soluble organic solvent is acetonitrile and/or methanol.

A method of analyzing phenylhydrazine content in a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient includes obtaining a first measured value by measuring a phenylhydrazine content of a standard solution including phenylhydrazine or a salt thereof, a first acidic water and a first water-soluble organic solvent and having a phenylhydrazine concentration of 0.01 μg/mL to 10 μg/mL, obtaining a second measured value by measuring a phenylhydrazine content in a sample solution including a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient, a second acidic water and a second water-soluble organic solvent, and detecting a phenylhydrazine content in a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient based on the first measured value and second measured value. The first acidic water is hydrochloric acid, and/or an aqueous acetic acid solution, the first water-soluble organic solvent is acetonitrile and/or methanol, the second acidic water is hydrochloric acid, and/or an aqueous acetic acid solution, and the second water-soluble organic solvent is acetonitrile and/or methanol.

A process for identifying an unknown compound in a sample includes matching a peak in a primary Fourier Transform Infrared spectral region of the sample spectrum with reference spectra in the same spectral region to generate an initial list of potential candidates, based, for example on goodness of fit criteria. The initial list can be reduced by retention time information and/or global peak matching techniques that analyze the sample spectrum in regions outside the primary region.

A method of analyzing phenylhydrazine content in a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient includes obtaining a first measured value by measuring a phenylhydrazine content of a standard solution including phenylhydrazine or a salt thereof, a first acidic water and a first water-soluble organic solvent and having a phenylhydrazine concentration of 0.01 μg/mL to 10 μg/mL, obtaining a second measured value by measuring a phenylhydrazine content in a sample solution including a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient, a second acidic water and a second water-soluble organic solvent, and detecting a phenylhydrazine content in a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient based on the first measured value and second measured value. The first acidic water is hydrochloric acid, and/or an aqueous acetic acid solution, the first water-soluble organic solvent is acetonitrile and/or methanol, the second acidic water is hydrochloric acid, and/or an aqueous acetic acid solution, and the second water-soluble organic solvent is acetonitrile and/or methanol.

A GC sample carbon ladder is generated with the help of one or more of the following techniques: correction of solvent effects; fit analysis of the spectrum obtained for a target member of the carbon ladder and a reference spectrum; fit analysis of a sample carbon ladder in comparison with reference spectral features; constraints for proper order of elution; and/or inclusion of all members in a selected carbon ladder set.

The present disclosure is directed to methods of characterizing a system containing a chromatographic column. The methods can include introducing a sample comprising a positive control and a negative control to the system containing a chromatographic column, wherein the positive control is a sensitive probe that interacts with the system and the negative control is substantially non-interacting with the system; after passing the sample through the chromatographic column, detecting the positive control and the negative control; and determining system suitability by comparing the amount of detected positive control to negative control. In some embodiments, determining system suitability (e.g., inertness of sample to the system) is accomplished by determining a ratio of detected positive control to negative control.

Parts are exposed to liquid chromatography to generate a corresponding chromatogram, wherein the chromatogram is compared to a chromatogram of a genuine part to determine if the tested part is suspect counterfeit. Depending on the selected predetermined target analytes, the generated chromatogram can be used to assess an associated manufacturing process as conforming or non-conforming.

Systems and methods for speciation of chemicals of interest with inline and automatic dilution or addition of other fluids prior to or following speciation with subsequent analysis by ICP instruments are described. A system embodiment includes, but is not limited to, a first valve having a first valve configuration to receive a sample into a holding loop coupled to the first valve and a second valve configuration to transfer the sample from the holding loop; and a second valve having a first valve configuration configured to receive the sample from the first valve and direct the sample to a speciation column to separate one or more species of the sample, the second valve further including a fluid addition port configured to receive a fluid into the second valve to mix with the sample after the sample exits the speciation column.

Calibrants and methods of making the same include using mixtures of multifunctional core compounds or multifunctional dendrimers that are functionalized to yield a set of discrete compounds which cover a range of collisional cross sections (CCSs) for calibrating ion mobility and variation in molecular weight to calibrate the mass to charge (m/z) measurements of mass spectrometry, as well as for calibrating tandem instruments that measure both dimensions. Methods of using the calibrants are also disclosed, such as in mass spectrometry.