Table 6 Nuclear magnetic resonance spectroscopy methods

TD-NMR

Chlorella protothecoides

Whole cells

Quantitative

Nile Red, lipid extraction/gravimetric

Less restriction than Nile Red, which cannot determine lipid content < 38%

[132]

¹H NMR, ¹³C NMR, 2D ¹H/¹³C NMR, liquid state

Ulva rigida, Gracilaria longa, Fucus virsoides, Codium tomentosum

Crude extracted lipids, Solvent extraction by Folch method

Mono- and polyunsaturated fatty acids, carotenes and carotenoids, steroids, chlorophylls; Qualitative

–

–

[120]

¹³C NMR Solid state

Chlamydomonas reinhardtii, Pavlova lutheri, Nannochloropsis oculata

Whole cells enriched with NaH¹³CO₃

Lipids, saccharides; Quantitative

–

Could not distinguish cell wall components with mobility

[123]

¹H LF-NMR

C. protothecoides

Whole cells, crude extracted lipids

Quantitative glyceryl trioleate internal standard

GC/MS

Extremely sensitive, limits of quantification 1.18 g/L, < 2% RSD, limit of detection 0.32 g/L (algal broth)

[130]

¹H NMR, 1H HR-MAS, liquid state

Chlorella, C. reinhardtii

Whole cells

TAGs; Quantitative, oleic TAG standard internal standard

GC

Biomonitoring

[125]

1D, 2D ¹H/¹³C solution state NMR

C. reinhardtii, Chlorella vulgaris, Synechocystis

¹³C labeled whole cells

Lipids, TAGs, among metabolites; Qualitative

–

Metabolic profiles

[124]

Liquid state ¹³C NMR, ³¹P NMR

Neochloris oleoabundans

Whole cells

TAGs; Qualitative, glyceryl trioleate standard

–

Interference from MAGs and DAGs, no contribution of phospholipids

[122]

ERETIC ¹H NMR

Thalassiosira weissflogii, Cyclotella cryptica, Nannochloropsis salina

Solvent-extracted lipids by Folch method

Free fatty acids, TAGs, glycolipids, phospholipids; Quantitative

–

Saturation degree, total lipid content, class distribution, profiling

[133]

¹H, ¹³C NMR, 1D, 2D

C. vulgaris, Scenedesmus ecornis

Extracted lipids

Unsaturated and saturated fatty acid esters, TAG, free fatty acids, polar lipids, standard: TGO, soybean, Jatropha oil and Mixoil14; Quantitative

GC/MS

Lipid profiling and quantification of extracts

[121]

¹H, ¹³C NMR

C. vulgaris, S. ecornis

Solvent-extracted lipids by chloroform:methanol:water

Neutral lipids (TAGs, free fatty acids), polar lipids (glyceroglycolipids, phospholipids) and unsaturation degree; Quantitative

GC/MS

Monitoring cultivations for biodiesel potential

[39]

HR MAS ¹H

NMR

Dunaliella sp., Amphidinium carterae, Phaedodactylum tricorutum, Thalassiosira pseudonana

Whole cells

Lipids, saturated, unsaturated; Qualitative

–

Profiling of whole cells

[128]

¹H NMR, ¹H HR MAS

Thalassiosira pseudonana

Extracts and whole cells

Important metabolites such as polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoic Acid; Qualitative

–

Lipid profiling

[134]

¹H NMR, ¹H HR MAS, ¹³C-NMR

Chaetoceros muelleri

Extracted lipids and whole cells

Important unsaturated fatty acids such as eicosapentaenoic and docosahexaenoic acids, phospholipids, and glycerols; Qualitative

–

Lipid profiling

[129]