nist_ri {webchem} | R Documentation |
Retrieve retention indices from NIST
Description
This function scrapes NIST for literature retention indices
given a query or vector of queries as input. The query can be a cas
number, IUPAC name, or International Chemical Identifier (inchikey
),
according to the value of the from
argument. Retention indices are
stored in tables by type
, polarity
and temperature program
(temp_prog
). The function can take multiple arguments for these
parameters and will return any retention times matching the specified
criteria in a single table.
If a non-cas query is provided, the function will try to resolve the query
by searching the NIST WebBook for a corresponding CAS number. If
from == "name"
, phonetic spellings of Greek stereo-descriptors
(e.g. "alpha", "beta", "gamma") will be automatically
converted to the corresponding letters to match the form used by NIST. If
a CAS number is found, it will be returned in a tibble
with the
corresponding information from the NIST retention index database.
Usage
nist_ri(
query,
from = c("cas", "inchi", "inchikey", "name"),
type = c("kovats", "linear", "alkane", "lee"),
polarity = c("polar", "non-polar"),
temp_prog = c("isothermal", "ramp", "custom"),
cas = NULL,
verbose = getOption("verbose")
)
Arguments
query |
character; the search term |
from |
character; type of search term. can be one of |
type |
Retention index type: |
polarity |
Column polarity: |
temp_prog |
Temperature program: |
cas |
deprecated. Use |
verbose |
logical; should a verbose output be printed on the console? |
Details
The types of retention indices included in NIST include Kovats
("kovats"
), Van den Dool and Kratz ("linear"
), normal alkane
("alkane"
), and Lee ("lee"
). Details about how these are
calculated are available on the NIST website:
https://webbook.nist.gov/chemistry/gc-ri/
Value
returns a tibble of literature RIs with the following columns:
query
is the query provided to the NIST servercas
is the CAS number or unique record identified used by NISTRI
is retention indextype
is the type of RI (e.g. "kovats", "linear", "alkane", or "lee")polarity
is the polarity of the column (either "polar" or "non-polar")temp_prog
is the type of temperature program (e.g. "isothermal", "ramp", or "custom")column
is the column type, e.g. "capillary"phase
is the stationary phase (column phase)length
is column length in metersgas
is the carrier gas usedsubstrate
diameter
is the column diameter in mmthickness
is the phase thickness in µmprogram
. various columns depending on the value oftemp_prog
reference
is where this retention index was publishedcomment
. I believe this denotes the database these data were aggregated from
Note
Copyright for NIST Standard Reference Data is governed by the Standard Reference Data Act, https://www.nist.gov/srd/public-law.
References
NIST Mass Spectrometry Data Center, William E. Wallace, director, "Retention Indices" in NIST Chemistry WebBook, NIST Standard Reference Database Number 69, Eds. P.J. Linstrom and W.G. Mallard, National Institute of Standards and Technology, Gaithersburg MD, 20899, doi:10.18434/T4D303.
See Also
Examples
## Not run:
myRIs <-
nist_ri(
c("78-70-6", "13474-59-4"),
from = "cas",
type = c("linear", "kovats"),
polarity = "non-polar",
temp_prog = "ramp"
)
myRIs
## End(Not run)