def get_chrom_time_min_max(chromatograms):
    """
    Get the highest and lowest retention times from a set of chromatograms.

    Parameters
    ----------
    chromatograms: list of Chromatogram objects.

    Returns
    -------
    max_time, min_time: float
    """
    max_time = 1e100
    min_time = 0

    for c in chromatograms:
        if c.time.min() > min_time:
            min_time = c.time.min()
        if c.time.max() < max_time:
            max_time = c.time.max()

    return min_time, max_time