Mass spectra of sulfonephthalein pH indicator dyes and their impurities

Description

Sulfonephthalein pH indicator dyes have historically been noted for impurities originating from the synthesis process which lead to batch to batch differences in pH measurements. Uncertainties up to 0.1 pH units have been attributed to impurities in these reagents. In an effort to understand the extent of impurities in these dyes and the potential impact on the expanded uncertainty of pH measured by this technique, we have examined seven commercially available sulfonephthalein pH indicators using liquid chromatography-mass spectrometry (LC-MS): bromocresol green (BCG), bromocresol purple (BCP), bromothymol blue (BTB), cresol red (CR), meta-cresol purple (MCP), phenol red (PR), and thymol blue (TB). Peaks eluting from the LC (Figure 1) were subjected to fragmentation by mass spectrometry. The resulting dataset will aid in efforts to improve the synthesis or purification of these dyes.

Resources

Name Format Description Link
47 https://opendata.nist.gov/1503_TB_AC1_3.cdf.sha256
47 https://opendata.nist.gov/1503_BCG_AA1_1.cdf.sha256
47 https://opendata.nist.gov/1503_BCP_AA1_3.cdf.sha256
47 https://opendata.nist.gov/1503_BTB_LG1_1.cdf.sha256
47 https://opendata.nist.gov/1503_MCP_PB1_2.cdf.sha256
47 https://opendata.nist.gov/1503_PR_AA1_1.cdf.sha256
47 https://opendata.nist.gov/1503_CR_AA1_1.cdf.sha256
47 https://opendata.nist.gov/1503_TB_AC1_2.cdf.sha256
47 https://opendata.nist.gov/1503_BCG_AA1_2.cdf.sha256
47 https://opendata.nist.gov/1503_BCP_AA1_2.cdf.sha256
47 https://opendata.nist.gov/1503_CR_AA1_3.cdf.sha256
0 https://doi.org/doi:10.18434/M3JP40
47 1503_BCP_AA1_1.cdf https://opendata.nist.gov/1503_BCP_AA1_1.cdf
47 https://opendata.nist.gov/1503_BTB_LG1_2.cdf.sha256
47 1503_MCP_PB1_1.cdf https://opendata.nist.gov/1503_MCP_PB1_1.cdf
47 https://opendata.nist.gov/1503_BCP_AA1_1.cdf.sha256
47 https://opendata.nist.gov/1503_PR_AA1_2.cdf.sha256
47 https://opendata.nist.gov/1503_TB_AC1_1.cdf.sha256
47 1503_CR_AA1_2.cdf https://opendata.nist.gov/1503_CR_AA1_2.cdf
47 1503_PR_AA1_3.cdf https://opendata.nist.gov/1503_PR_AA1_3.cdf
47 1503_BCG_AA1_3.cdf https://opendata.nist.gov/1503_BCG_AA1_3.cdf
47 1503_BCP_AA1_2.cdf https://opendata.nist.gov/1503_BCP_AA1_2.cdf
47 1503_BCG_AA1_2.cdf https://opendata.nist.gov/1503_BCG_AA1_2.cdf
47 1503_CR_AA1_3.cdf https://opendata.nist.gov/1503_CR_AA1_3.cdf
47 https://opendata.nist.gov/1503_BTB_LG1_3.cdf.sha256
47 https://opendata.nist.gov/1503_BCG_AA1_3.cdf.sha256
47 1503_MCP_PB1_3.cdf https://opendata.nist.gov/1503_MCP_PB1_3.cdf
47 1503_BCG_AA1_1.cdf https://opendata.nist.gov/1503_BCG_AA1_1.cdf
47 https://opendata.nist.gov/1503_MCP_PB1_3.cdf.sha256
47 1503_MCP_PB1_2.cdf https://opendata.nist.gov/1503_MCP_PB1_2.cdf
47 https://opendata.nist.gov/1503_CR_AA1_2.cdf.sha256
47 https://opendata.nist.gov/1503_PR_AA1_3.cdf.sha256
47 1503_BTB_LG1_2.cdf https://opendata.nist.gov/1503_BTB_LG1_2.cdf
47 1503_PR_AA1_2.cdf https://opendata.nist.gov/1503_PR_AA1_2.cdf
47 1503_BTB_LG1_3.cdf https://opendata.nist.gov/1503_BTB_LG1_3.cdf
47 1503_TB_AC1_1.cdf https://opendata.nist.gov/1503_TB_AC1_1.cdf
47 1503_BCP_AA1_3.cdf https://opendata.nist.gov/1503_BCP_AA1_3.cdf
47 1503_BTB_LG1_1.cdf https://opendata.nist.gov/1503_BTB_LG1_1.cdf
47 1503_TB_AC1_3.cdf https://opendata.nist.gov/1503_TB_AC1_3.cdf
47 1503_PR_AA1_1.cdf https://opendata.nist.gov/1503_PR_AA1_1.cdf
47 https://opendata.nist.gov/1503_MCP_PB1_1.cdf.sha256
47 1503_CR_AA1_1.cdf https://opendata.nist.gov/1503_CR_AA1_1.cdf
47 1503_TB_AC1_2.cdf https://opendata.nist.gov/1503_TB_AC1_2.cdf

Tags

  • ph-indicators
  • seawater-ph
  • mass-spectrometry

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