Authors: Nisha Shabnam Indu Tripathi P Sharmila P PardhaSaradhi
Publish Date: 2015/11/16
Volume: 253, Issue: 6, Pages: 1577-1582
Abstract
Proline a stress marker is routinely quantified by a protocol that essentially uses hazardous toluene Negative impacts of toluene on human health prompted us to develop a reliable alternate protocol for proline quantification Absorbance of the prolineninhydrin condensation product formed by reaction of proline with ninhydrin at 100 °C in the reaction mixture was significantly higher than that recorded after its transfer to toluene revealing that toluene lowers sensitivity of this assay λ max of the prolineninhydrin complex in the reaction mixture and toluene were 508 and 513 nm respectively Ninhydrin in glacial acetic acid yielded higher quantity of the prolineninhydrin condensation product compared to ninhydrin in mixture of glacial acetic acid and H3PO4 indicating negative impact of H3PO4 on proline quantification Further maximum yield of the prolineninhydrin complex with ninhydrin in glacial acetic acid and ninhydrin in mixture of glacial acetic acid and H3PO4 was achieved within 30 and 60 min respectively This revealed that H3PO4 has negative impact on the reaction rate and quantity of the prolineninhydrin complex formed In brief our proline quantification protocol involves reaction of a 1ml proline sample with 2 ml of 125 ninhydrin in glacial acetic acid at 100 °C for 30 min followed by recording absorbance of the prolineninhydrin condensation product in the reaction mixture itself at 508 nm Amongst proline quantification protocols known till date our protocol is the most simple rapid reliable costeffective and ecofriendlier
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