Today we have only samhitA portion of paippalAda shAkhA. There are few traces of lost brAhman portion . It was also known as paippalAda gopatha brAhman / paippalAda brAhman .
Even srI sankarAcharya quotes a mantra from lost brAhman / lost aranyaka portion of paippalAda shAkhA in his bramhasutra bhAshya .
[ bramha sutra 3.3.25 ]
( The last phrase of mantra is traced at PS 1.76.4cd but that’s not upanishada Arambha .)
At another instance he made citation from paippalAda samhitA.( 8.9.11 )
From this two example it is clear that till the time of Acharya , paippalAda shAkhA was studied with brAhman and Aranyaka bhAga and srI shankarAcharya was familiar with it. Next to him venkata mAdhava ( commentator of rig veda ) in his rigvedAnukramAnI , referred to paippalAda brAhman.
” SrI dhara” who is author ( prayoga+ paddhati kAra of paippalAda shAkhA ) of “karmapanjikA ” quoted many untraceable verses from gopatha brAhman .” My opinion is that they are from lost paippalAda brAhman .”
( Some verses quoted on behalf of Gopatha , are traced in atharvaveda parishishTha. )
For example a “madakarma brAhman” quoted in vedavrata section of karmapanjikA is untraceable , I think it belongs to lost paippalAda brAhman.
A treatise “prapapanch hridaya ” of unknown authorship also informs us of paippalAda brAhman.
” paippalAda shAkhA ( samhitA ) have 20 kAndas , which have riks and yajus , where yajus are in majority. Total number of mantras are 12,300.The paippalAda brAhman have 8 adhyAyas , containing explanation of divya ( adhbhutAni ) , sAmpradAyika ( of yagniks i.e. of vedic sacrifices ) ,prAyachhita ( atonement ) , abhichAra ( mantric attack ).”
On the basis of all this pramAns ( proofs ) following are my hypothetical conclusion on lost paippalAda brAhman .
” paippalAda brAhman contains 100 prapAthaks within the 8 adhyAyas ( chapters ) and is divided in 2 bramhans i.e. purva brAhman and Uttara brAhman .The total number of kandikAs are 5000 , in which 1000 are mantras ( riks ) and remaining 4000 are brAhmanical prose .It covers following four subjects .
1) divya ( adhbhutAni )
2) sAmpradAyika ( explanation of vedic sacrifices , upanishads like prashna etc belongs to this section .)
3) prAyachhita ( atonement during any unfavorable condition )
4) abhichAra ( mantric attack ). ”