Table 3. Frequency of kidney stone analysis showing disagreement between chemical and FT-IR method (n=77).
| Results by chemical method | Results by FT-IR | Stone no. |
|---|---|---|
| Pure calcium oxalate (n=67) | Mixed COM, COD, carbonate apatite | 17 |
| Mixed magnesium ammonium phosphate hexahydrate, carbonate apatite | 8 | |
| Mixed COD, uric acid | 8 | |
| Mixed COM, magnesium ammonium phosphate hexahydrate, carbonate apatite | 7 | |
| Mixed COM, COD, uric acid | 6 | |
| Mixed COD, magnesium ammonium phosphate hexahydrate, carbonate apatite | 3 | |
| Mixed COM, COD, ammonium urate | 3 | |
| Mixed COD, ammonium urate | 2 | |
| Mixed COM, uric acid | 2 | |
| Mixed COD, carbonate apatite | 2 | |
| Pure carbonate apatite | 2 | |
| Pure magnesium ammonium phosphate hexahydrate | 2 | |
| Mixed COM, cystine | 1 | |
| Mixed COM, COD, magnesium ammonium phosphate hexahydrate | 1 | |
| Mixed COD, ammonium urate | 1 | |
| Mixed COM, carbonate apatite, ammonium hydrogen urate | 1 | |
| Mixed cystine, carbonate apatite | 1 | |
| Mixed calcium oxalate and uric acid (n=5) | Mixed COM, COD, uric acid | 2 |
| Mixed COD, uric acid | 2 | |
| Mixed COM, uric acid | 1 | |
| Pure uric acid (n=4) | Mixed COD, uric acid | 3 |
| Mixed COM, carbonate apatite, calcium monohydrogen phosphate dihydrate | 1 | |
| Pure calcium phosphate (n=1) | Mixed COM, magnesium ammonium phosphate hexahydrate, carbonate apatite | 1 |
FT-IR, Fourier transform infrared; COM, calcium oxalate monohydrate; COD, calcium oxalate dihydrate.