nist_ri: Retrieve retention indices from NIST

Description

This function scrapes NIST for literature retention indices given CAS numbers as an input.

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
)

Arguments

query

character; the search term

from

character; type of search term. can be one of "name", "inchi", "inchikey", or "cas". Using an identifier is preferred to "name" since NA is returned in the event of multiple matches to a query. Using an identifier other than a CAS number will cause this function to run slower as CAS numbers are used as internal identifiers by NIST.

type

Retention index type. One of "kovats", "linear", "alkane", or "lee". See details for more.

polarity

Column polarity. One of "polar" or "non-polar" to get RIs calculated for polar or non-polar columns.

temp_prog

Temperature program. One of "isothermal", "ramp", or "custom".

cas

deprecated. Use query instead.

Value

returns a tibble of literature RIs with the following columns:

CAS is the CAS number
type is the column type, e.g. "capillary"
phase is the stationary phase (column phase)
RI is retention index
length is column length in meters
gas is the carrier gas used
substrate
diameter is the column diameter in mm
thickness is the phase thickness in <U+00B5>m
program. various columns depending on the value of temp_prog
reference is where this retention index was published
comment. I believe this denotes the database these data were aggregated from

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/

Examples

Run this code

# NOT RUN {
myRIs <- nist_ri(c("78-70-6", "13474-59-4"), from = "cas", "linear",
"non-polar", "ramp")
# }