『(Abstract)
　Little is known about P species in agro-industrial byproducts from developing countries, which may be either pollutants or valuable soil amendments. The present study speciated P in dry (COD) and wet (COW) coffee, sisal (SIS), barley malt (BEB) and sugar cane processing (FIC) byproducts, and filter cakes of linseed (LIC) and niger seed (NIC) with sequential fractionation, solution ³¹P nuclear magnetic resonance (NMR) spectroscopy, and P K- and L2,3-edge X-ray absorption near-edge structure (XANES) spectroscopy. The sequential P fractionation recovered 59％ to almost 100％ of total P (Pt), and more than 50％ of Pt was extracted by H2O and NaHCO3 in five out of seven samples. Similarly, the NaOH + EDTA extraction for solution ³¹P NMR recovered 48-94％ of Pt. The ³¹P NMR spectra revealed orthophosphate (6-81％), pyrophosphate (0-10％), and orthophosphate monoesters (6-94％). Orthophosphate predominated in COD, COW, SIS. and FIC, whereas BEB, LIC, and NIC were rich orthophosphate monoesters. The concentrations of Pi and Po determined in the sequential and NaOH + EDTA extractions and ³¹P NMR spectra were strongly and positively correlated (r = 0.88-1.99). Furthermore, the P K- and L2,3-edge XANES confirmed the H2SO4-Pi detected in the sequential fractionation by unequivocal identification of Ca-P phases in a few samples. The results indicate that the combined use of all four analytical methods is crucial for comprehensive P speciation in environmental samples and the application of these byproducts to soil.』

Introduction
Materials and methods
　Sample collection and preparation
　Sequential P fractionation
　Solution ³¹P NMR analysis
　P L-edge X-ray Absorption Near-Edge Structure spectroscopy
　L2,3-edge X-ray Absorption Near-Edge Structure spectroscopy
Results and Discussion
　Sequentially extracted P fractions
　NaOH + EDTA-extracts and solution ³¹P NMR spectra
　P K- and L2,3-edge X-ray Absorption Near-Edge Structure spectroscopy
Acknowledgments
Supporting information available
Literature cited