Why does \ttabbox from floatrow make the caption slightly to long

Question

I have the following problem, I am trying to make the caption of my table as big as the table itself. The floatrow package seems to do the trick. But in my case the caption for a reason I do not understand is always slightly to long - about 0.2 cm or so. No idea how to change that, help would be very much appreciated.

Minimal working example:

  \documentclass[a4paper]{article}
  \usepackage[english]{babel}
  \usepackage{siunitx}
  \DeclareSIUnit\Molar{M}
  \DeclareSIUnit\rpm{rpm}

  \usepackage{caption}

  \usepackage{floatrow}

  \begin{document}

  \begin{table}[!htb]

  \ttabbox{
  \caption{Concentrations used to prepare the sulfitolysis buffers. Literature references refer to the source of the 
  $Na_{2}SO_{3}$ and $Na_{2}S_{4}O_{3}$ concent...} 
  }{

  \begin{tabular}{llllll}
  \hline
  Name  & $Na_{2}S_{4}O_{3}$ & GuHCl & Urea & pH & Lit.  \\ 

  S1      &     \SI{20}{\milli\Molar}    & -     &  \SI{8}{\Molar} & 8.3  \\ 
  S2      &     \SI{80}{\milli\Molar}    & \SI{7}{\Molar} &  -  & 7.3  \\ 
  S3     &  \SI{80}{\milli\Molar}    & \SI{7}{\Molar} &  -  & 9.3 \\ 

  \end{tabular}
  }

  \end{table}

  \end{document}

What I get is:

score 2 · Answer 1 · edited Feb 03 '16 at 00:26

You have unprotected end-of-lines, which I inserted and marked.

I also made some changes to the table, using S columns and moving the units to the header (feel free to undo these changes) and used mhchem with the \ce command for chemical formulas.

Avoid ! in the position specifier and remember to add p.

\documentclass[a4paper]{article}
\usepackage[english]{babel}

\usepackage{booktabs}
\usepackage{caption}
\usepackage{floatrow}
\usepackage[version=4]{mhchem}
\usepackage{siunitx}
\DeclareSIUnit\Molar{M}
\DeclareSIUnit\rpm{rpm}

\begin{document}

\begin{table}[htbp]

\ttabbox{% <--- missing
  \caption{Concentrations used to prepare the sulfitolysis buffers. 
    Literature references refer to the source of the 
    \ce{Na2SO3} and \ce{Na2S4O3} concent...}% <--- MISSING
  }{% <--- MISSING
  \begin{tabular}{
    l
    S[table-format=2.0]
    S[table-format=1.0]
    S[table-format=1.0]
    S[table-format=1.1]
    c
  }
  \toprule
  Name & {\ce{Na2S4O3}}        & {Gu\ce{HCl}}    & {Urea}          & {pH} & Lit.  \\
       & {(\si{\milli\Molar})} & {(\si{\Molar})} & {(\si{\Molar})} \\
  \midrule
  S1   & 20    & {--} & 8    & 8.3  \\ 
  S2   & 80    & 7    & {--} & 7.3  \\ 
  S3   & 80    & 7    & {--} & 9.3 \\ 
  \bottomrule
  \end{tabular}% <--- MISSING
}

\end{table}

\end{document}

The same output can be obtained in a less demanding way with threeparttable:

\documentclass[a4paper]{article}
\usepackage[english]{babel}

\usepackage{booktabs}
\usepackage{caption}
\usepackage{threeparttable}
\usepackage[version=4]{mhchem}
\usepackage{siunitx}
\DeclareSIUnit\Molar{M}
\DeclareSIUnit\rpm{rpm}

\begin{document}

\begin{table}[htbp]
\centering

\begin{threeparttable}

\caption{Concentrations used to prepare the sulfitolysis buffers. 
    Literature references refer to the source of the 
    \ce{Na2SO3} and \ce{Na2S4O3} concent...}

\begin{tabular}{
  l
  S[table-format=2.0]
  S[table-format=1.0]
  S[table-format=1.0]
  S[table-format=1.1]
  c
}
\toprule
Name & {\ce{Na2S4O3}}        & {Gu\ce{HCl}}    & {Urea}          & {pH} & Lit.  \\
     & {(\si{\milli\Molar})} & {(\si{\Molar})} & {(\si{\Molar})} \\
\midrule
S1   & 20    & {--} & 8    & 8.3  \\ 
S2   & 80    & 7    & {--} & 7.3  \\ 
S3   & 80    & 7    & {--} & 9.3 \\ 
\bottomrule
\end{tabular}

\end{threeparttable}

\end{table}

\end{document}

Why does \ttabbox from floatrow make the caption slightly to long

1 Answers1