Alternative capillary column to 30% G22 phase support S1D

in ether USP monograph (2-mm × 3.7-m stainless steel; with 30% phase G22 on 30- to 60-mesh support S1D) is required for "Limit of Low-Boiling Hydrocarbons" analysis but it is packed column,  and we want to find alternative capillary column.

Thanks in advance.

Damián Walton 

Parents
  • Hi Damian,

    G22 is Bis(2-ethylhexyl) phthalate and there is no capillary equivalent (see also GC and GC/MS Columns - USP Designations). Even as packed phase it falls under REACH as carcinogenic chemical and we don't offer it anymore.

    Looking at the McReynolds constants for BEHP the closest capillary phases would be CP-Sil 19 CB/VF-1701ms, VF-35ms or DB-Alc2, all slightly less polar and a changed selectivity.

    Phase Class McR1 McR2 McR3 McR4 McR5 Euclidean
    Distance
    Cosine
    Similarity
    CP-Index
    Bis(2-ethylhexyl) phthalate, BEHP Packed 92 186 150 236 167 0.0000 1.0000 19.7
    USP G22 Packed 92 186 150 236 167 0.0000 1.0000 19.7
    DB-ALC2 Capillary 84 172 159 241 161 0.0913 0.9981 19.4
    CP-Sil 19 CB Capillary 82 170 157 236 160 0.0980 0.9983 19.1
    VF-1701ms Capillary 82 170 157 236 160 0.0980 0.9983 19.1
    VF-35ms Capillary 80 179 146 224 188 0.1212 0.9964 19.4

    Regards,

    Norbert

Reply
  • Hi Damian,

    G22 is Bis(2-ethylhexyl) phthalate and there is no capillary equivalent (see also GC and GC/MS Columns - USP Designations). Even as packed phase it falls under REACH as carcinogenic chemical and we don't offer it anymore.

    Looking at the McReynolds constants for BEHP the closest capillary phases would be CP-Sil 19 CB/VF-1701ms, VF-35ms or DB-Alc2, all slightly less polar and a changed selectivity.

    Phase Class McR1 McR2 McR3 McR4 McR5 Euclidean
    Distance
    Cosine
    Similarity
    CP-Index
    Bis(2-ethylhexyl) phthalate, BEHP Packed 92 186 150 236 167 0.0000 1.0000 19.7
    USP G22 Packed 92 186 150 236 167 0.0000 1.0000 19.7
    DB-ALC2 Capillary 84 172 159 241 161 0.0913 0.9981 19.4
    CP-Sil 19 CB Capillary 82 170 157 236 160 0.0980 0.9983 19.1
    VF-1701ms Capillary 82 170 157 236 160 0.0980 0.9983 19.1
    VF-35ms Capillary 80 179 146 224 188 0.1212 0.9964 19.4

    Regards,

    Norbert

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