Since you are referring to there being data from two different sequencer types the following should work. There are unique barcodes on flowcells from different types of sequencers. Following also assumes that fastq headers have not been modified in any way.

Out the following code in a file (barcode.awk) :

BEGIN { FS = ":"; }

((NR % 4) == 1) { barcodes[$3]++; }

END {
  for (bc in barcodes) {
            print bc": "barcodes[bc]"";
    }
}

then run like this: zcat your.fastq.gz | awk -f barcode.awk. It should tell you if you have one or more barcodes represented along with the number of reads for each type. If your data is not compressed then cat your.fastq | awk -f barcode.awk should be used.